Uemura Tetsuya(Faculty of Information Science and Technology　Electronics for Informatics　Advanced Electronics)

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Uemura Tetsuya

Faculty of Information Science and Technology　Electronics for Informatics　Advanced Electronics Professor
Institute for Frontier Education and Research on Semiconductors Professor

Researcher basic information

■ Nickname etc.

植村哲也

■ Degree

博士（工学）, 京都大学

■ URL
researchmap URL

https://researchmap.jp/read0118420?lang=en

ホームページURL

https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200901018152363278

http://www.ist.hokudai.ac.jp/labo/nanodev/index.html

http://www.ist.hokudai.ac.jp/labo/nanodev/index_english.html

■ Various IDs
J-Global ID

200901018152363278

■ Research Keywords and Fields
Research Keyword

spin transistor

spintronics

トンネル磁気抵抗

強磁性トンネル接合

スピン注入

磁気ランダムアクセスメモリ

半導体

スピンLED

トンネル異方性磁気抵抗効果

共鳴トンネルダイオード

Co系ホイスラー合金

スピン依存トンネリング

スピン輸送特性

ハーフメタル強磁性体

先端デバイス開発

Research Field

Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering), Electron device and electronic equipment

Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering), Electric and electronic materials

■ Educational Organization

Bachelor's degree program, School of Engineering

Master's degree program, Graduate School of Information Science and Technology

Doctoral (PhD) degree program, Graduate School of Information Science and Technology

Career

■ Career
Career

Apr. 2016 - Present
Hokkaido University, Graduate School of Information Science and Technology, Professor

Apr. 2007 - Mar. 2016
Graduate School of Information Science and Technology, Hokkaido Universtiy, Associate Professor

Apr. 2004 - Mar. 2007
Graduate School of Information Science and Technology, Hokkaido University, Associate Professor

Jan. 2002 - Mar. 2004
Graduate School of Engineering, Hokkaido University, Associate Professor

Apr. 1990 - Dec. 2001
Fundamental Reseach Laboratory, NEC Corporation

Educational Background

Apr. 1988 - Mar. 1990, Kyoto University, Graduate School of Engineering, Division of Electrical Engineering

Apr. 1984 - Mar. 1988, Kyoto University, Facalty of Engineering, Department of Electrical Engineering

Research activity information

■ Papers

Nonlocal Detection of Current-Induced Magnetization Dynamics in Microfabricated Pt/CoFe/n-GaAs Heterostructure
Varun Kumar Kushwaha; Mineto Ogawa; Tetsuya Uemura; Takeshi Seki
2025 International Conference on Solid State Devices and Materials, 126, 2, Sep. 2025, [Peer-reviewed]
English, International conference proceedings

Current-induced effective magnetic field acting on a domain wall in perpendicularly magnetized Pd/Co2MnGa
Takaya Koyama; Yuki Nishioka; Tetsuya Uemura; Michihiko Yamanouchi
AIP Advances, 15, 3, AIP Publishing, 01 Mar. 2025, [Peer-reviewed]
English, Scientific journal, We investigated the current-induced effective magnetic field Heff acting on a domain wall (DW) under an in-plane magnetic field H// along the current direction in a perpendicularly magnetized heterostructure composed of a Pd and Weyl ferromagnet Co2MnGa (CMG) layer. Heff is equivalent to a perpendicular magnetic field to move the DW. The magnitude of Heff per current density had a local maximum with respect to H// and decreased at large |H//|. This relationship cannot be explained only by Heff originating from the conventional spin-orbit torque and/or orbit torque (SOT/OT). Assuming that the residual component of Heff excluding the contribution of SOT/OT originates from the conventional field-like spin-transfer torque, the lower bound of the nonadiabaticity parameter characterizing the torque, which is usually much less than 1, is estimated to be 1.9. These results suggest that unconventional and energy-efficient mechanisms are superposed on the SOT/OT in Pd/CMG.

Binary neural networks with giant conductance changes in Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
R. Kusunose; T. Marukame; T. Uemura
2025 Joint MMM-Intermag Conference, Feb. 2025, [Peer-reviewed], [Last author]
English, International conference proceedings

In-plane magnetic field dependence of torque exerted on a domain wall in Pd/Co2MnGa
T. Koyama; Y. Nishioka; T. Uemura; M. Yamanouchi
2025 Joint MMM-Intermag Conference, Feb. 2025, [Peer-reviewed]
English, International conference proceedings

Spin injection and detection using perpendicularly magnetized Mn/Co bilayers grown on GaAs via all electrical methods
Mineto Ogawa; Kotaro Nara; Michihiko Yamanouchi; Tetsuya Uemura
APPLIED PHYSICS LETTERS, 126, 2, 13 Jan. 2025, [Peer-reviewed], [Corresponding author]
English, Scientific journal

Observations of Non-Local Spin-Valve Signal and Hanle Signal in Perpendicularly Magnetized Mn/Co/n-GaAs Junctions via All Electrical Methods
M. Ogawa; K. Nara; M. Yamanouchi; T. Uemura
2025 Joint MMM-Intermag Conference, Jan. 2025, [Corresponding author]
English, International conference proceedings

Fabrication of a near-infrared spin photodiode using dilute nitride GaNAs
T. Yano; D. Mineyama; K. Etou; K. Nakama; H. Hashimoto; K. Minehisa; M. Ogawa; J. Takayama; F. Ishikawa; T. Uemura; A. Murayama; S. Hiura
37th International Microprocesses and Nanotechnology Conference (MNC 2024), Nov. 2024, [Peer-reviewed]
English, International conference proceedings

Electrical Detection of Magnetization Reversal via Magnetoresistance of MnGa/GaAs Junction
Mineto Ogawa; Michiko Yamanouchi; Tetsuya Uemura
23rd International Conference on Molecular-Beam Epitaxy (ICMBE2024), Sep. 2024, [Peer-reviewed], [Corresponding author]
English, International conference proceedings

Perspective on spin-based wave-parallel computing
Makoto Kohda; Takeshi Seki; Yasushi Yuminaka; Tetsuya Uemura; Keito Kikuchi; Gian Salis
Appl. Phys. Lett., 123, 190502, Nov. 2023, [Peer-reviewed], [Invited]
English, Scientific journal

Current-induced domain wall motion in Pd/Co2MnGa with perpendicular magnetic anisotropy
Takaya Koyama; Yuki Nishioka; Tetsuya Uemura; Michihiko Yamanouchi
68th Annual Conference on Magnetism and Magnetic Materials, Abstracts,, VP1-01, Oct. 2023, [Peer-reviewed]
English, International conference proceedings

Effect of an ultrathin Fe interlayer on the growth of MnGa and spin-orbit-torque induced magnetization switching
Mineto Ogawa; Takuya Hara; Shun Hasebe; Michihiko Yamanouchi; Tetsuya Uemura
Applied Physics Express, 16, 6, 063002, 063002, IOP Publishing, 01 Jun. 2023, [Peer-reviewed], [Corresponding author]
English, Scientific journal, Abstract

We investigated the effect of an ultrathin Fe interlayer on the growth of MnGa and spin–orbit torque (SOT) induced magnetization switching. MnGa was epitaxially grown on Fe at room temperature without thermal annealing. The MnGa/Fe bilayer was perpendicularly magnetized, and clear magnetization switching of the MnGa/Fe bilayer using the spin current, mainly from the adjacent Ta, was observed. The insertion of the Fe layer reduced the switching current density and increased a SOT-originated effective magnetic field. These results indicate that the MnGa/Fe bilayer is a promising spin source, capable of both perpendicular spin injection into GaAs and electrical manipulation of its spin direction.

Microfabrication and Characterization of Ferromagnetic Metal/Nonmagnetic Semiconductor Junctions for Spin Pumping-Induced Highly Efficient Spin Injection
T.S. Balland; T. Seki; T. Yamazaki; R.Y. Umetsu; M. Ogawa; T. Uemura; K. Takanashi
IEEE International Magnetics Conference 2023 (INTERMAG 2023), Digest Book, DPB-08, May 2023, [Peer-reviewed]
English, International conference proceedings

Spin-orbit torque induced magnetization switching in perpendicularly magnetized MnGa/Fe bilayer grown on GaAs
Mineto Ogawa; Takuya Hara; Shun Hasebe; Michihiko Yamanouchi; Tetsuya Uemura
IEEE International Magnetics Conference 2023 (INTERMAG 2023), Digest Book, APC-08, May 2023, [Peer-reviewed], [Corresponding author]
English, International conference proceedings

Deterministic field-free switching of perpendicular magnetization by spin–orbit torques originating from in-plane magnetized Co2MnAl
Daimu Morita; Takuya Hara; Michihiko Yamanouchi; Tetsuya Uemura
AIP Advances, 13, 1, AIP Publishing, 01 Jan. 2023, [Peer-reviewed], [Corresponding author]
English, Scientific journal, Spin–orbit torques (SOTs) induced magnetization switching in a perpendicularly magnetized CoFeB film deposited on a Ti/in-plane magnetized Co2MnAl stack was investigated. Deterministic switching of the CoFeB magnetization was demonstrated by applying a current pulse to the stack in a direction parallel or antiparallel to the Co2MnAl magnetization. We found that the hysteresis loops of the anomalous Hall resistance for CoFeB under the constant current is shifted in the out-of-plane magnetic field axis direction depending on the directions of both the applied current and the magnetization of Co2MnAl. The shift amount exhibits an almost linear increase as the current magnitude increases. These results are consistent with the effects caused by SOTs originating from spin currents having an in-plane polarization orthogonal to the Co2MnAl magnetization.

Field-free switching of perpendicular magnetization by spin-orbit torques originating from an in-plane magnetized Co2MnAl spin source
Daimu Morita; Takuya Hara; Michihiko Yamanouchi; Tetsuya Uemura
67th Annual Conference on Magnetism and Magnetic Materials, Abstracts,, EOE-14, Oct. 2022, [Peer-reviewed], [Corresponding author]
English, International conference proceedings

Effect of off-stoichiometric composition on half-metallic character of Co₂Fe(Ga,Ge) investigated using saturation magnetization and giant magnetoresistance effect
Yuki Chikaso; Masaki Inoue; Tessei Tanimoto; Keita Kikuchi; Michihiko Yamanouchi; Tetsuya Uemura; Kazuumi Inubushi; Katsuyuki Nakada; Hikari Shinya; Masafumi Shirai
Journal of Physics D: Applied Physics, 55, 34, 345003 (9pp), IOP Publishing, 25 Aug. 2022, [Peer-reviewed], [Corresponding author]
English, Scientific journal, Abstract

We investigated the Ge-composition (γ) dependence of the saturation magnetization of Co₂Fe(Ga, Ge) (CFGG) thin films and the magnetoresistance (MR) ratio of CFGG-based current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) devices together with first-principles calculations of the electronic states of CFGG. Theoretical calculations showed that spin polarization is highest at the stoichiometric composition γ = 0.56 in Co₂Fe_1.03Ga_0.41Ge_γ and that it decreases in off-stoichiometric CFGG, mainly due to the formation of Co_Fe antisites for Ge-deficient compositions and Fe_Co antisites for Ge-rich compositions, where Co_Fe (Fe_Co) indicates that Co (Fe) atoms replace the Fe (Co) sites. The saturation magnetic moment (μ_s) per formula unit decreased monotonically as γ increased from 0.24 to 1.54 in Co₂Fe_1.03Ga_0.41Ge_γ. The μ_s was closest to the Slater–Pauling value predicted for half-metallic CFGG at the stoichiometric composition γ = 0.56, indicating that stoichiometric CFGG has a half-metallic nature. This is consistent with the result for the theoretical spin polarization. In contrast, the MR ratio of CFGG-based CPP-GMR devices increased monotonically as γ increased from 0.24 to 1.10 and reached an MR ratio of 87.9% at the Ge-rich composition γ = 1.10. Then, the MR ratio decreased rapidly as γ increased from 1.10 to 1.48. Possible origins for the slight difference between the Ge composition at which the highest MR ratio was obtained (γ = 1.10) and that at which the highest spin polarization was obtained (γ = 0.56) are improved atomic arrangements in a Ge-rich CFGG film and the reduction of effective Ge composition due to Ge diffusion in the GMR stacks.

Theory and observation of topological Hall torque emerging from band topology
Y. Araki; M. Yamanouchi; T. Sakai; T. Uemura; J. Ieda
29th International Conference on LOW TEMPERATURE PHYSICS (LT29), Aug. 2022, [Peer-reviewed]
English, International conference proceedings

Spin-Orbit Torque in Structures With Magnetization-Compensated MnGa/Co₂MnSi Bilayer
Takuya Hara; Kohey Jono; Michihiko Yamanouchi; Tetsuya Uemura
IEEE Transactions on Magnetics, 58, 8, 1400104 (4pp), 4, Institute of Electrical and Electronics Engineers (IEEE), Aug. 2022, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal

Observation of topological Hall torque exerted on a domain wall in the ferromagnetic oxide SrRuO ₃
Michihiko Yamanouchi; Yasufumi Araki; Takaki Sakai; Tetsuya Uemura; Hiromichi Ohta; Jun’ichi Ieda
Science Advances, 8, 15, eabl6192(6pp), American Association for the Advancement of Science (AAAS), 15 Apr. 2022, [Peer-reviewed]
English, Scientific journal, In a ferromagnetic Weyl metal SrRuO ₃ , a large effective magnetic field H_eff exerted on a magnetic domain wall (DW) by current has been reported. We show that the ratio of H_eff to current density exhibits nonmonotonic temperature dependence and surpasses those of conventional spin-transfer torques and spin-orbit torques. This enhancement is described well by topological Hall torque (THT), which is exerted on a DW by Weyl electrons emerging around Weyl points when an electric field is applied across the DW. The ratio of the H_eff arising from the THT to current density is over one order of magnitude higher than that originating from spin-transfer torques and spin-orbit torques reported in metallic systems, showing that the THT may provide a better way for energy-efficient manipulation of magnetization in spintronics devices.

Spin-orbit torque in structures with magnetization-compensated MnGa/Co2MnSi bilayer
T. Hara; K. Jono; M. Yamanouchi; T. Uemura
15th Joint MMM-Intermag Conference, 360, Jan. 2022, [Peer-reviewed], [Last author, Corresponding author]
English, International conference proceedings

Nonmonotonic temperature dependence of current induced effective magnetic field exerted on domain wall in SrRuO₃
M. Yamanouchi; Y. Araki; T. Sakai; T. Uemura; H. Ohta; J. Ieda
15th Joint MMM-Intermag Conference, 386, Jan. 2022, [Peer-reviewed]
English, International conference proceedings

Spin–orbit torque induced magnetization switching for an ultrathin MnGa/Co2MnSi bilayer
Kohey Jono; Fumiaki Shimohashi; Michihiko Yamanouchi; Tetsuya Uemura
AIP Advances, 11, 2, 025205(5pp), AIP Publishing, 01 Feb. 2021, [Peer-reviewed], [Corresponding author]
English, Scientific journal

MnGa/Co2MnSi Bilayer for Spin-Orbit Torque Magnetization Switching
M. Yamanouchi; K. Jono; F. Shimohashi; T. Uemura
65th Annual Conference on Magnetism and Magnetic Materials, Abstracts,, R2-07, Nov. 2020, [Peer-reviewed], [Last author]
English, International conference proceedings

Enhancement of magnetoresistance characteristics of Ge-rich Co2Fe(Ga,Ge)-based current-perpendicular-to-plane giant magnetoresistance devices
K. Nakada; Y. Chikaso; T. Tanimoto; M. Inoue; K. Inubushi; T. Uemura
65th Annual Conference on Magnetism and Magnetic Materials, Abstracts,, R3-12, Nov. 2020, [Peer-reviewed], [Corresponding author]
English, International conference proceedings

Spin-orbit-torque induced magnetization switching for an ultra-thin MnGa/Co2MnSi bilayer
K. Jono; F. Shimohashi; M. Yamanouchi; T. Uemura
2020 International Conference on Solid State Devices and Materials (SSDM2020), Extended Abstracts, 599, 600, Sep. 2020, [Peer-reviewed], [Corresponding author]
English, International conference proceedings

Off-stoichiometry effect on magnetic damping in thin films of Heusler alloy Co2MnSi
Ting Li; Wei Yan; Xinhui Zhang; Bing Hu; Kidist Moges; Tetsuya Uemura; Masafumi Yamamoto; Masahito Tsujikawa; Masafumi Shirai; Yoshio Miura
Physical Review B, 101, 17, 174410(12pp), American Physical Society (APS), 06 May 2020, [Peer-reviewed]
English, Scientific journal

Magnetic properties and spin-orbit-torque-induced magnetization switching in Ta/MnGa grown on Cr and NiAl buffer layers
Michihiko Yamanouchi; Nguyen Viet Bao; Fumiaki Shimohashi; Kohey Jono; Masaki Inoue; Tetsuya Uemura
AIP ADVANCES, 9, 12, 125245-1, 125245-4, Dec. 2019, [Peer-reviewed], [Last author]
English, Scientific journal

Effects of spin–orbit torque on domain wall motion in a Ta/MnGa/NiAl structure
M. Yamanouchi; N.V. Bao; M. Inoue; T. Uemura
64th Annual Conference on Magnetism and Magnetic Materials, Abstracts,, p.773, Nov. 2019, [Peer-reviewed], [Last author]
English, International conference proceedings

Spin-orbit-torque induced magnetization switching for an ultra-thin MnGa grown on NiAl buffer layer
Shimohashi Fumiaki; Nguyen Bao; Yamanouchi Michihiko; Uemura Tetsuya
JSAP Annual Meetings Extended Abstracts, 2019.2, 2176, 2176, The Japan Society of Applied Physics, 04 Sep. 2019
English

Interaction between spin-orbit torque and domain walls in a Ta/MnGa/NiAl structure
M. Yamanouchi; N. V. Bao; M. Inoue; T. Uemura
Jpn. J. Appl. Phys., vol.58, 10, 100903-1, 100903-4, Sep. 2019, [Peer-reviewed], [Last author]
English, Scientific journal

Origin of biquadratic interlayer exchange coupling in Co2MnSi-based current-perpendicular-to-plane pseudo spin valves
M. Inoue; K. Inubushi; D. Mouri; T. Tanimoto; K. Nakada; K. Kondo; M. Yamamoto; T. Uemura
Appl. Phys. Lett., vol.114, 062401(5pp), Feb. 2019, [Peer-reviewed], [Corresponding author]
English, Scientific journal

Electrical spin injection into an AlGaAs/GaAs-based 2DEG system with a Co2MnSi spin source up to room temperature
Z. Lin; D. Pan; M. Rasly; T. Uemura
14th Joint MMM-Intermag Conference, Abstracts, 86, Jan. 2019, [Peer-reviewed], [Corresponding author]
English, International conference proceedings

Electrical spin injection into AlGaAs/GaAs-based two-dimensional electron gas systems with Co2MnSi spin source up to room temperature
Z. Lin; D. Pan; M. Rasly; T. Uemura
Appl. Phys. Lett., vol.114, 1, 012405(5pp), AIP Publishing, Jan. 2019, [Peer-reviewed], [Corresponding author]
English, Scientific journal

Origin of bi-quadratic interlayer exchange coupling in Co2MnSi-based pseudo spin valves
D. Mouri; M. Inoue; K. Inubushi; T. Tanimoto; K. Nakada; M. Yamamoto; T. Uemura
2018 International Conference on Solid State Devices and Materials (SSDM2018), Extended Abstracts, PS-9-08, Sep. 2018, [Peer-reviewed], [Corresponding author]
English, International conference proceedings

Mn-composition dependence of strength of bi-quadratic interlayer exchange coupling in Co2MnSi-based pseudo spin-valves
M. Inoue; D. Mouri; K. Inubushi; K. Nakada; M. Yamamoto; T. Uemura
IEEE International Magnetics Conference 2018 (INTERMAG 2018), Digest Book, 855, Apr. 2018, [Peer-reviewed], [Corresponding author]
English, International conference proceedings

Electrical spin injection into an AlGaAs/GaAs-based high-mobility two-dimensional electron system
Z. Lin; D. Pan; M. Rasly; T. Uemura
IEEE International Magnetics Conference 2018 (INTERMAG 2018), Digest Book, p.1616, Apr. 2018, [Peer-reviewed], [Corresponding author]
English, International conference proceedings

Coherent manipulation of nuclear spins in GaAs using electrical spin injection
T. Uemura
International Workshop on NanoScience and NanoOptics 2017, Nov. 2017, [Invited]
English, International conference proceedings

Systematic investigations of transient response of nuclear spins in the presence of polarized electrons
Mohmoud Rasly; Zhichao Lin; Tetsuya Uemura
PHYSICAL REVIEW B, 96, 18, 184415(8pp), Nov. 2017, [Peer-reviewed]
English, Scientific journal

Influence of Mn composition in Co2MnSi films on magnetoresistance characteristics of Co2MnSi-based current-perpendicular-to-plane spin valves
M. Inoue; B. Hu; K. Moges; K. Inubushi; K. Nakada; M. Yamamoto; T. Uemura
2017 International Conference on Solid State Devices and Materials (SSDM2017), Extended Abstracts, 989, 990, Sep. 2017, [Peer-reviewed]
International conference proceedings

Influence of off-stoichiometry on magnetoresistance characteristics of Co2MnSi/Ag-based current-perpendicular-to-plane spin valves
Masaki Inoue; Bing Hu; Kidist Moges; Kazuumi Inubushi; Katsuyuki Nakada; Masafumi Yamamoto; Tetsuya Uemura
APPLIED PHYSICS LETTERS, 111, 8, 082403(5pp), Aug. 2017, [Peer-reviewed]
English, Scientific journal

Influence of Mn composition in Co2MnSi films on magnetoresistance characteristics of Co2MnSi-based giant magneto-resistance devices
M. Inoue; B. Hu; K. Moges; K. Inubushi; K. Nakada; M. Yamamoto; T. Uemura
9th International School and Conference on Spintronics and Quantum Information Technology, Abstract Book, 85, Jun. 2017, [Peer-reviewed]
English, International conference proceedings

Electrical detection of nuclear spin-echo signals in an electron spin injection system
Zhichao Lin; Mahmoud Rasly; Tetsuya Uemura
APPLIED PHYSICS LETTERS, 110, 23, 232404 (4pp), Jun. 2017, [Peer-reviewed]
English, Scientific journal

Electrical control of nuclear spin polarization: Experimental and quantitative modeling
M. Rasly; Z. Lin; M. Yamamoto; T. Uemura
IEEE Int’l Magnetics Conf. 2017 (INTERMAG 2017), Digests (USB Memory), GO-12, Apr. 2017, [Peer-reviewed]
English, International conference proceedings

Fabrication of a Spin Injection Device Having a Top-gate Structure
W. Nomura; T. Miyakawa; M. Yamamoto; T. Uemura
2016 International Conference on Solid State Devices and Materials (SSDM2016), Extended Abstracts, 921, 922, Sep. 2016, [Peer-reviewed]
English, International conference proceedings

Temperature dependence of spin-dependent tunneling conductance of magnetic tunnel junctions with half-metallic Co2MnSi electrodes
Bing Hu; Kidist Moges; Yusuke Honda; Hong-xi Liu; Tetsuya Uemura; Masafumi Yamamoto; Jun-ichiro Inoue; Masafumi Shirai
PHYSICAL REVIEW B, 94, 9, 094428(15pp), Sep. 2016, [Peer-reviewed]
English, Scientific journal

Highly efficient spin injection from a half-metallic spin source of Co2MnSi and sensitive detection of nuclear spin states
T. Uemura
The 18th International Conference on Crystal Growth and Epitaxy (ICCGE18), Technical Digest, 243, Aug. 2016, [Invited]
English, International conference proceedings

Spin diffusion and non-local spin-valve effect in an exfoliated multilayer graphene with a Co electrode
Lijun Li; Inyeal Lee; Dongsuk Lim; Servin Rathi; Moonshik Kang; Tetsuya Uemura; Gil-Ho Kim
NANOTECHNOLOGY, 27, 33, 335201(6pp), Aug. 2016, [Peer-reviewed]
English, Scientific journal

Impact of CoFe buffer layers on the structural and electronic properties of the Co2MnSi/MgO interface
Roman Fetzer; Hong-xi Liu; Benjamin Stadtmueller; Tetsuya Uemura; Masafumi Yamamoto; Martin Aeschlimann; Mirko Cinchetti
JOURNAL OF PHYSICS D-APPLIED PHYSICS, 49, 19, 195002(5pp), May 2016, [Peer-reviewed]
English, Scientific journal

Analysis of the transient response of nuclear spins in GaAs with/without nuclear magnetic resonance
Mahmoud Rasly; Zhichao Lin; Masafumi Yamamoto; Tetsuya Uemura
AIP ADVANCES, 6, 5, 056305(8pp), May 2016, [Peer-reviewed]
English, Scientific journal

Enhanced half-metallicity of off-stoichiometric quaternary Heusler alloy Co-2(Mn, Fe)Si investigated through saturation magnetization and tunneling magnetoresistance
Kidist Moges; Yusuke Honda; Hong-xi Liu; Tetsuya Uemura; Masafumi Yamamoto; Yoshio Miura; Masafumi Shirai
PHYSICAL REVIEW B, 93, 13, 134403(15pp), Apr. 2016, [Peer-reviewed]
English, Scientific journal

Transient analysis of oblique Hanle signals observed in GaAs
Zhichao Lin; Kenji Kondo; Masafumi Yamamoto; Tetsuya Uemura
JAPANESE JOURNAL OF APPLIED PHYSICS, 55, 4, 04EN03 (5pp), Apr. 2016, [Peer-reviewed]
English, Scientific journal

Efficient gate control of spin-valve signals and Hanle signals in GaAs channel with p-i-n junction-type back-gate structure
Takumi Miyakawa; Takafumi Akiho; Yuya Ebina; Masafumi Yamamoto; Tetsuya Uemura
APPLIED PHYSICS EXPRESS, 9, 2, 023103(4pp), Feb. 2016, [Peer-reviewed]
English, Scientific journal

Effect of nonstoichiometry on the half-metallic character of Co2MnSi and its application to the spin sources of spintronic devices
Masafumi Yamamoto; Tetsuya Uemura
Springer Series in Materials Science, 222, 413, 444, Springer Verlag, 01 Jan. 2016, [Peer-reviewed]
English, In book

Coherent manipulation of nuclear spins using spin injection from a half-metallic spin source
Tetsuya Uemura; Takafumi Akiho; Yuya Ebina; Masafumi Yamamoto
SPINTRONICS IX, 9931, 55, 2016, [Invited]
English, International conference proceedings

Coherent manipulation of nuclear spins using spin injection from a half-metallic spin source
Tetsuya Uemura; Takafumi Akiho; Yuya Ebina; Masafumi Yamamoto
SPINTRONICS IX, 9931, 99311L-1, 99311L-7, 2016, [Invited]
English, International conference proceedings

Analysis of transient response of nuclear spins in GaAs with/without nuclear magnetic resonance
M. Rasly; Z. Lin; M. Yamamoto; T. Uemura
13th Joint MMM-Intermag Conference, Abstracts, 278, 279, Jan. 2016, [Peer-reviewed]
English, International conference proceedings

Coherent manipulation of nuclear spins using spin injection from a half-metallic spin source
Tetsuya Uemura; Takafumi Akiho; Yuya Ebina; Masafumi Yamamoto
SPINTRONICS IX, 9931, 140410(R)(5pp), 99311L-7, 2016, [Peer-reviewed], [Invited]
English, International conference proceedings

Bias Voltage Dependence of the Spin-dependent Tunneling Conductance of Co2(Mn,Fe)Si-Based Magnetic Tunnel Junctions Exhibiting Giant Tunneling Magnetoresistances
Kidist Moges; B. Hu; H.x. Liu; T. Uemura; M. Yamamoto
2015 Intrnational Conference on Solid State Devices and Materials (SSDM2015), Extended Abstracts (DVD, USB memory), 408, 409, Sep. 2015, [Peer-reviewed]
English, International conference proceedings

Temperature Dependence of Spin-Dependent Tunneling Conductance of Magnetic Tunnel Junctions with Highly Spin-Polarized Electrodes
B. Hu; Kidist. Moges; H.x. Liu; Y. Honda; T. Uemura; M. Yamamoto
2015 Intrnational Conference on Solid State Devices and Materials (SSDM2015), Extended Abstracts (DVD, USB memory), 410, 411, Sep. 2015, [Peer-reviewed]
English, International conference proceedings

Transient Analysis of Oblique Hanle Signals Observed in GaAs
Z.c. Lin; M. Yamamoto; T. Uemura
2015 Intrnational Conference on Solid State Devices and Materials (SSDM2015), Extended Abstracts (DVD, USB memory), 432, 433, Sep. 2015, [Peer-reviewed]
English, International conference proceedings

Investigation of spin lifetime in strained InxGa1-xAs channels through all-electrical spin injection and detection
Takafumi Akiho; Masafumi Yamamoto; Tetsuya Uemura
APPLIED PHYSICS EXPRESS, 8, 9, 093001(4pp), Sep. 2015, [Peer-reviewed]
English, Scientific journal

Coherent control of nuclear spins using spin injection from half-metallic Co2MnSi
T. Akiho; Y. Ebina; M. Yamamoto; T. Uemura
21st International Conference on Electronic Properties of Two-Dimensional Systems, Abstracts, vol.91, 186, Jul. 2015, [Peer-reviewed]
English, International conference proceedings

Gate control of spin-valve signal and Hanle signal in GaAs observed by a four-terminal nonlocal geometry
T. Miyakawa; T. Akiho; Y. Ebina; M. Yamamoto; T. Uemura
17th International Conference on Modulated Semiconductor Structures, Abstracts, 158, Jul. 2015, [Peer-reviewed]
English, International conference proceedings

Coherent manipulation of nuclear spins using spin injection from a half-metallic spin source
Tetsuya Uemura; Takafumi Akiho; Yuya Ebina; Masafumi Yamamoto
PHYSICAL REVIEW B, 91, 14, Apr. 2015, [Peer-reviewed]
English, Scientific journal

Spin-resolved low-energy and hard x-ray photoelectron spectroscopy of off-stoichiometric Co2MnSi Heusler thin films exhibiting a record TMR
Roman Fetzer; Siham Ouardi; Yusuke Honda; Hong-xi Liu; Stanislav Chadov; Benjamin Balke; Shigenori Ueda; Motohiro Suzuki; Tetsuya Uemura; Masafumi Yamamoto; Martin Aeschlimann; Mirko Cinchetti; Gerhard H. Fecher; Claudia Felser
JOURNAL OF PHYSICS D-APPLIED PHYSICS, 48, 16, 164002(12pp), Apr. 2015, [Peer-reviewed]
English, Scientific journal

Influence of film composition in quaternary Heusler alloy Co-2(Mn,Fe)Si thin films on tunnelling magnetoresistance of Co-2(Mn,Fe)Si/MgO-based magnetic tunnel junctions
Hong-xi Liu; Takeshi Kawami; Kidist Moges; Tetsuya Uemura; Masafumi Yamamoto; Fengyuan Shi; Paul M. Voyles
JOURNAL OF PHYSICS D-APPLIED PHYSICS, 48, 16, 164001(9pp), Apr. 2015, [Peer-reviewed]
English, Scientific journal

Probing the electronic and spintronic properties of buried interfaces by extremely low energy photoemission spectroscopy
Roman Fetzer; Benjamin Stadtmueller; Yusuke Ohdaira; Hiroshi Naganuma; Mikihiko Oogane; Yasuo Ando; Tomoyuki Taira; Tetsuya Uemura; Masafumi Yamamoto; Martin Aeschlimann; Mirko Cinchetti
SCIENTIFIC REPORTS, 5, 8537(6pp), Feb. 2015, [Peer-reviewed]
English, Scientific journal

Manipulation of nuclear spins in GaAs using a half-metallic spin source of Co2MnSi.
T. Uemura; M. Yamamoto
2015 IEEE MAGNETICS CONFERENCE (INTERMAG), CC-01, 2015, [Invited]
English, International conference proceedings

Half-metallic electronic structure of Co-2(Mn,Fe)Si electrodes investigated through tunneling spectroscopy for fully epitaxial magnetic tunnel junctions.
K. Moges; H. Liu; T. Kawami; T. Uemura; M. Yamamoto
2015 IEEE MAGNETICS CONFERENCE (INTERMAG), GB-06, 2015, [Peer-reviewed]
English, International conference proceedings

Temperature dependence of spin-dependent tunneling resistances of Co2MnSi-based and Co-2(Mn,Fe)Si-based magnetic tunnel junctions showing high tunneling magnetoresistances.
B. Hu; H. Liu; T. Kawami; K. Moges; Y. Honda; T. Uemura; M. Yamamoto
2015 IEEE MAGNETICS CONFERENCE (INTERMAG), GB-11, 2015, [Peer-reviewed]
English, International conference proceedings

Spin transport and spin conversion in compound semiconductor with non-negligible spin-orbit interaction
Akiyori Yamamoto; Yuichiro Ando; Teruya Shinjo; Tetsuya Uemura; Masashi Shiraishi
PHYSICAL REVIEW B, 91, 2, 024417(6pp), Jan. 2015, [Peer-reviewed]
English, Scientific journal

Effect of nonstoichiometry on the half-metallicity of Co2(Mn,Fe)Si thin films investigated through saturation magnetization
Kidist Moges; Y. Honda; T. Uemura; M.Yamamoto; Y. Miura; M. Shirai
59th Annual Conference on Magnetism and Magnetic Materials, Abstracts, 48, 49, Nov. 2014, [Peer-reviewed]
English, International conference proceedings

Electrical detection of nuclear magnetic resonance in GaAs using transient oblique Hanle effect measurements
T. Uemura; T. Akiho; Y. Ebina; M. Yamamoto
59th Annual Conference on Magnetism and Magnetic Materials, Abstracts,, 671, 672, Nov. 2014, [Peer-reviewed]
English, International conference proceedings

Efficient nuclear spin polarization and electrical detection of nuclear magnetic resonance in GaAs using half-metallic spin source
T. Uemura; M. Yamamoto
The 3rd Internaional Conference of Asian Union of Magnetics Societies, Abstracts, p.263, Oct. 2014, [Invited]
English, International conference proceedings

Efficient Dynamic Nuclear Polarization Using Electrical Spin Injection from a Half-Metallic Spin Source
T. Akiho; Y. Ebina; H.-x. Liu; M. Yamamoto; T. Uemura
32nd International Conference on the Physics of Semiconductors (ICPS2014), Abstracts, Spintronics & Spin phenomena II, 2, 3, Aug. 2014, [Peer-reviewed]
English, International conference proceedings

Highly efficient spin injection and dynamic nuclear polarization using a half-metallic spin source
Tetsuya UEMURA
The 6th IEEE International Nanoelectronics Conference 2014 (IEEE INEC 2014), Abstracts, Jul. 2014, [Invited]
English, International conference proceedings

Electrical spin injection from ferromagnet into an InAs quantum well through a MgO tunnel barrier
Tomotsugu Ishikura; Lenanrt-Knud Liefeith; Zhixin Cui; Keita Konishi; Kanji Yoh; Tetsuya Uemura
APPLIED PHYSICS EXPRESS, 7, 7, 073001(4pp), Jul. 2014, [Peer-reviewed]
English, Scientific journal

Dependence of degree of temperature dependence of TMR ratio of Co2MnSi/MgO/Co2MnSi MTJs on Mn composition in Co2MnSi electrodes
Y. Honda; H.-x. Liu; T. Uemura; M. Yamamoto
IEEE Int’l Magnetics Conf. 2014 (INTERMAG 2014), Digests (USB Memory), 2407, 2408, May 2014, [Peer-reviewed]
English, Scientific journal

Effect of CoFe insertion in Co2MnSi/CoFe/n-GaAs junctions on spin injection properties
Yuya Ebina; Takafumi Akiho; Hong-xi Liu; Masafumi Yamamoto; Tetsuya Uemura
APPLIED PHYSICS LETTERS, 104, 17, 172405(4pp), Apr. 2014, [Peer-reviewed]
English, Scientific journal

Probing the electronic states of high-TMR off-stoichiometric Co 2 MnSi thin films by hard x-ray photoelectron spectroscopy
Xeniya Kozina; Julie Karel; Siham Ouardi; Stanislav Chadov; Gerhard H. Fecher; Claudia Felser; Gregory Stryganyuk; Benjamin Balke; Takayuki Ishikawa; Tetsuya Uemura; Masafumi Yamamoto; Eiji Ikenaga; Shigenori Ueda; Keisuke Kobayashi
Physical Review B - Condensed Matter and Materials Physics, 89, 12, American Physical Society, 17 Mar. 2014, [Peer-reviewed]
English, Scientific journal

Probing the electronic states of high-TMR off-stoichiometric Co2MnSi thin films by hard x-ray photoelectron spectroscopy
Xeniya Kozina; Julie Karel; Siham Ouardi; Stanislav Chadov; Gerhard H. Fecher; Claudia Felser; Gregory Stryganyuk; Benjamin Balke; Takayuki Ishikawa; Tetsuya Uemura; Masafumi Yamamoto; Eiji Ikenaga; Shigenori Ueda; Keisuke Kobayashi
PHYSICAL REVIEW B, 89, 12, 125116(10pp), Mar. 2014, [Peer-reviewed]
English, Scientific journal

Effect of nonstoichiometry on the half-metallic character of Co2 MnSi investigated through saturation magnetization and tunneling magnetoresistance ratio
Gui-Fang Li; Yusuke Honda; Hong-Xi Liu; Ken-Ichi Matsuda; Masashi Arita; Tetsuya Uemura; Masafumi Yamamoto; Yoshio Miura; Masafumi Shirai; Toshiaki Saito; Fengyuan Shi; Paul M. Voyles
Physical Review B - Condensed Matter and Materials Physics, 89, 1, 30 Jan. 2014, [Peer-reviewed]
English, Scientific journal

Effect of nonstoichiometry on the half-metallic character of Co2MnSi investigated through saturation magnetization and tunneling magnetoresistance ratio
Gui-fang Li; Yusuke Honda; Hong-xi Liu; Ken-ichi Matsuda; Masashi Arita; Tetsuya Uemura; Masafumi Yamamoto; Yoshio Miura; Masafumi Shirai; Toshiaki Saito; Fengyuan Shi; Paul M. Voyles
PHYSICAL REVIEW B, 89, 1, 014428(14pp), Jan. 2014, [Peer-reviewed]
English, Scientific journal

Effect of CoFe insertion on spin injection properties of Co2MnSi/CoFe/n-GaAs junctions
Y. Ebina; T. Akiho; H. Liu; M. Yamamoto; T. Uemura
58th Annual Conference on Magnetism and Magnetic Materials, Abstracts, vol.58, p.108, AX-01, Nov. 2013, [Peer-reviewed]
English, International conference proceedings

Giant tunnel magnetoresistance in fully epitaxial Co2(Mn,Fe)Si/MgO/Co2(Mn,Fe)Si magnetic tunnel junctions
T. Kawami; H. Liu; Y. Honda; K. M. Ayele; T. Uemura; F. Shi; P. M. Voyles; M. Yamamoto
58th Annual Conference on Magnetism and Magnetic Materials, Abstracts, vol.58, p.614, FX-03, Nov. 2013, [Peer-reviewed]
English, International conference proceedings

Spin and symmetry properties of the buried Co2MnSi/MgO interface.
R. Fetzer; Y. Ohdaira; H. Naganuma; M. Oogane; Y. Ando; T. Taira; T. Uemura; M. Yamamoto; M. Aeschlimann; M. Cinchetti
58th Annual Conference on Magnetism and Magnetic Materials, Abstracts, vol.58, p.626, GB-14, Nov. 2013, [Peer-reviewed]
English, International conference proceedings

Spin-dependent transport properties of strained InGaAs channel investigated through all electrical spin injection and detection
T. Akiho; M. Yamamoto; T. Uemura
58th Annual Conference on Magnetism and Magnetic Materials, Abstracts, vol.58, p.716, HB-10, Nov. 2013, [Peer-reviewed]
English, International conference proceedings

Electrical injection of spin-polarized electrons and electrical detection of dynamic nuclear polarization using a Heusler alloy spin source
Takafumi Akiho; Jinhai Shan; Hong-Xi Liu; Ken-Ichi Matsuda; Masafumi Yamamoto; Tetsuya Uemura
Physical Review B - Condensed Matter and Materials Physics, 87, 23, 17 Jun. 2013, [Peer-reviewed]
English, Scientific journal

Electrical injection of spin-polarized electrons and electrical detection of dynamic nuclear polarization using a Heusler alloy spin source
Takafumi Akiho; Jinhai Shan; Hong-xi Liu; Ken-ichi Matsuda; Masafumi Yamamoto; Tetsuya Uemura
PHYSICAL REVIEW B, 87, 23, 235205 (7pp), Jun. 2013, [Peer-reviewed]
English, Scientific journal

Structural, chemical, and electronic properties of the Co 2MnSi(001)/MgO interface
Roman Fetzer; Jan-Peter Wüstenberg; Tomoyuki Taira; Tetsuya Uemura; Masafumi Yamamoto; Martin Aeschlimann; Mirko Cinchetti
Physical Review B - Condensed Matter and Materials Physics, 87, 18, 17 May 2013, [Peer-reviewed]
English, Scientific journal

Structural, chemical, and electronic properties of the Co2MnSi(001)/MgO interface
Roman Fetzer; Jan-Peter Wuestenberg; Tomoyuki Taira; Tetsuya Uemura; Masafumi Yamamoto; Martin Aeschlimann; Mirko Cinchetti
PHYSICAL REVIEW B, 87, 18, 184418 (7pp), May 2013, [Peer-reviewed]
English, Scientific journal

Influence of interfacial structural properties on tunnel magnetoresistance in epitaxial magnetic tunnel junctions with Co2MnSi electrode and MgO barrier
H.-x. Liu; Y. Honda; K.-i. Matsuda; M. Arita; T. Uemura; M. Yamamoto
12th Joint MMM/Intermag Conf., Abstracts (USB memory), vol.12, p.507, EI-09, Jan. 2013, [Peer-reviewed]
English, International conference proceedings

Transient effects on oblique Hanle signals observed in ferromagnet/semiconductor heterojunctions with non-local four-terminal configuration
T. Akiho; J.-h. Shan; K.-i. Matsuda; M. Yamamoto; T. Uemura
12th Joint MMM/Intermag Conf., Abstracts (USB memory), vol.12, p.871, HR-04, Jan. 2013, [Peer-reviewed]
English, International conference proceedings

Enhanced coherent tunneling contribution in epitaxial magnetic tunnel junctions with a Co2MnSi electrode and a MgO barrier due to improved interfacial structural properties
H.-x. Liu; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 2nd Int’l Conf. of Asia Union of Magnetics Societies (ICAUMS 2012), The 36th Annual Conf. on Magnetics in Japan, Abstracts, vol2, p.28, 2pD-4, Oct. 2012, [Peer-reviewed]
English, International conference proceedings

Tunnel barrier thickness dependence of Hanle-type signals in CoFe/MgO/n-Ge tunnel junctions investigated through three-terminal configuration
G.-f. Li; M. Miki; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 17th Int’l Conf. on Molecular Beam Epitaxy (MBE 2012), Abstracts, vol17, p.5, MoA-1-2, Sep. 2012, [Peer-reviewed]
English, International conference proceedings

Tunnel barrier thickness dependence of Hanle-type signals in CoFe/MgO/n-Si and CoFe/MgO/n-Ge junctions investigated through three-terminal configuration
T. Uemura; G.-f. Li; J. Fujisawa; K. Kondo; K.-i. Matsuda; M. Yamamoto
2012 Int’l Conf. on Solid State Devices and Materials (SSDM 2012), Extended Abstracts (USB Memory), pp.1223-1224, K-9-4, Sep. 2012, [Peer-reviewed]
English, International conference proceedings

Transient oblique Hanle signals observed in Co2MnSi/CoFe/n-GaAs with non-local four-terminal configuration
J.-h. Shan; T. Akiho; K.-i. Matsuda; M. Yamamoto; T. Uemura
2012 Int’l Conf. on Solid State Devices and Materials (SSDM 2012), Extended Abstracts (USB Memory), pp.1219-1220, K-9-2, Sep. 2012, [Peer-reviewed]
English, International conference proceedings

Temperature dependence of spin-dependent tunneling resistances of MgO-buffered Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
Y. Honda; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
2012 Int’l Conf. on Solid State Devices and Materials (SSDM 2012), Extended Abstracts (USB Memory), pp.1197-1198, K-6-4, Sep. 2012, [Peer-reviewed]
English, International conference proceedings

Fabrication of Fully Epitaxial CoFe/MgO/CoFe Magnetic Tunnel Junctions on Ge(001) Substrates via a MgO Interlayer
Gui-fang Li; Tomoyuki Taira; Hong-xi Liu; Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
JAPANESE JOURNAL OF APPLIED PHYSICS, 51, 9, 093003 (5pp), Sep. 2012, [Peer-reviewed]
English, Scientific journal

Highly Spin-Polarized Tunneling in Epitaxial Magnetic Tunnel Junctions with a Co2MnSi Electrode and a MgO Barrier with Improved Interfacial Structural Properties
Hong-xi Liu; Yusuke Honda; Ken-ichi Matsuda; Masashi Arita; Tetsuya Uemura; Masafumi Yamamoto
JAPANESE JOURNAL OF APPLIED PHYSICS, 51, 9, 093004 (9pp), Sep. 2012, [Peer-reviewed]
English, Scientific journal

Critical effect of spin-dependent transport in a tunnel barrier on enhanced Hanle-type signals observed in three-terminal geometry
Tetsuya Uemura; Kenji Kondo; Jun Fujisawa; Ken-ichi Matsuda; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 101, 13, 132411 (4pp), Sep. 2012, [Peer-reviewed]
English, Scientific journal

Giant tunneling magnetoresistance in epitaxial Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions by half-metallicity of Co2MnSi and coherent tunneling
Hong-xi Liu; Yusuke Honda; Tomoyuki Taira; Ken-ichi Matsuda; Masashi Arita; Tetsuya Uemura; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 101, 13, 132418 (5pp), Sep. 2012, [Peer-reviewed]
English, Scientific journal

Spin-polarization measurements for Co?2MnSi using Co2MnSi/MgO/NbN epitaxial tunnel junctions
Ken-ichi Matsuda; Takaho Shinoki; Tomoyuki Taira; Tetsuya Uemura; Masafumi Yamamoto
The 19th Int’l Conf. on Magnetism (ICM2012), Abstracts of ICM2012, vol.19, p.351, SK06, Jul. 2012, [Peer-reviewed]
English, International conference proceedings

MgO thickness dependence of spin accumulation signal in Co50Fe50/MgO/Si
T. Uemura; J. Fujisawa; K.-i. Matsuda; M. Yamamoto
Int’l Magnetics Conf. 2012 (INTERMAG 2012), Digest (USB Memory), AD-06, May 2012, [Peer-reviewed]
English, International conference proceedings

Electrical spin injection from Co2MnSi Heusler alloy into GaAs and electrical detection of dynamic nuclear polarization
T. Akiho; T. Uemura; K.-i. Matsuda; M. Yamamoto
Int’l Magnetics Conf. 2012 (INTERMAG 2012), Digest (USB Memory), AD-03, May 2012, [Peer-reviewed]
English, International conference proceedings

Temperature dependence of spin-dependent tunneling conductances of fully epitaxial Co2MnSi-based magnetic tunnel junctions
H.-x. Liu; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Magnetics Conf. 2012 (INTERMAG 2012), Digest (USB Memory), EB-10, May 2012, [Peer-reviewed]
English, International conference proceedings

Possibility of Superconducting Proximity Effect of Equal-spin Triplet Components in NbN/Co2Cr0.6Fe0.4Al/NbN Junctions
Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
Int’l Conf. on Topological Quantum Phenomena (TQP2012), Abstracts of TQP2012, vol.1, p.149, PB23, May 2012, [Peer-reviewed]
English, International conference proceedings

Surface spin polarization of the nonstoichiometric Heusler alloy Co 2MnSi
Jan-Peter Wüstenberg; Roman Fetzer; Martin Aeschlimann; Mirko Cinchetti; Jan Minár; Jürgen Braun; Hubert Ebert; Takayuki Ishikawa; Tetsuya Uemura; Masafumi Yamamoto
Physical Review B - Condensed Matter and Materials Physics, 85, 6, 15 Feb. 2012, [Peer-reviewed]
English, Scientific journal

Surface spin polarization of the nonstoichiometric Heusler alloy Co2MnSi
Jan-Peter Wuestenberg; Roman Fetzer; Martin Aeschlimann; Mirko Cinchetti; Jan Minar; Juergen Braun; Hubert Ebert; Takayuki Ishikawa; Tetsuya Uemura; Masafumi Yamamoto
PHYSICAL REVIEW B, 85, 6, 064407 (10pp), Feb. 2012, [Peer-reviewed]
English, Scientific journal

Effect of MgO Barrier Insertion on Spin-Dependent Transport Properties of CoFe/n-GaAs Heterojunctions
Takafumi Akiho; Tetsuya Uemura; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto
JAPANESE JOURNAL OF APPLIED PHYSICS, 51, 2, 02BM01 (5pp), Feb. 2012, [Peer-reviewed]
English, Scientific journal

Non-local electrical detection of Hanle signals in Co2MnSi/Co50Fe50/n-GaAs Schottky tunnel junctions
T. Akiho; T. Uemura; H. Harada; K.-i., Matsuda; M. Yamamoto
56th Annual Conf. on Magnetism & Magnetic Materials, Abstracts (USB Memory), vol.56, p.471, GB-12, Nov. 2011, [Peer-reviewed]
English, International conference proceedings

Almost identical oscillations in tunneling resistances as a function of barrier thickness for parallel and antiparallel configurations for fully epitaxial magnetic tunnel junctions with a MgO barrier
Y. Honda; S. Hirata; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
56th Annual Conf. on Magnetism & Magnetic Materials, Abstracts (USB Memory), vol.56, p.426, FP-01, Nov. 2011, [Peer-reviewed]
English, International conference proceedings

Fabrication of epitaxial magnetic tunnel junctions with a Co2MnSi thin film and a MgO barrier on Ge(001) substrates via a MgO interlayer
G.-f. Li; T.Taira; H.-x. Liu; K. -i. Matsuda; T. Uemura; M. Yamamoto
56th Annual Conf. on Magnetism & Magnetic Materials, Abstracts (USB Memory), vol.56, p.251, DE-04, Nov. 2011, [Peer-reviewed]
English, International conference proceedings

Spin-dependent transport properties of fully epitaxial magnetic tunnel junctions of CoFe/MgO/CoFe ultrathin layer/Co2MnSi
H.-x. Liu; T. Taira; Y. Honda; K. -i. Matsuda; T. Uemura; M. Yamamoto; Y. Miura; M. Shirai
56th Annual Conf. on Magnetism & Magnetic Materials, Abstracts (USB Memory), vol.56, p.260, DE-01, Nov. 2011, [Peer-reviewed]
English, International conference proceedings

Effect of MgO Barrier Insertion on Spin-dependent Transport Properties of CoFe/n-GaAs
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto
2011 Int’l Conf. on Solid State Devices and Materials, Extended Abstracts (USB memory), pp.1460-1461,, Sep. 2011, [Peer-reviewed]
English, International conference proceedings

Fabrication of fully epitaxial magnetic tunnel junctions with CoFe electrodes and a MgO barrier on Ge(001) substrates via a MgO interlayer
G.-f. Li; T. Taira; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
2011 Int’l Conf. on Solid State Devices and Materials, Extended Abstracts (USB memory), pp.1448-1449,, Sep. 2011, [Peer-reviewed]
English, International conference proceedings

Effect of GaAs Surface Structure on Tunneling Anisotropic Magnetoresistance in Epitaxial Co50Fe50/n-GaAs Junctions
T. Uemura; T. Akiho; M. Harada; K.-i. Matsuda; M. Yamamoto
2011 Int’l Conf. on Solid State Devices and Materials, Extended Abstracts (USB memory), pp.448-449, P-12-9, Sep. 2011, [Peer-reviewed]
English, International conference proceedings

Magnetic dichroism in angle-resolved hard x-ray photoemission from buried layers
Xeniya Kozina; Gerhard H. Fecher; Gregory Stryganyuk; Siham Ouardi; Benjamin Balke; Claudia Felser; Gerd Schoenhense; Eiji Ikenaga; Takeharu Sugiyama; Naomi Kawamura; Motohiro Suzuki; Tomoyuki Taira; Tetsuya Uemura; Masafumi Yamamoto; Hiroaki Sukegawa; Wenhong Wang; Koichiro Inomata; Keisuke Kobayashi
PHYSICAL REVIEW B, 84, 5, 054449 (8pp), Aug. 2011, [Peer-reviewed]
English, Scientific journal

Non-local detection of spin-polarized electrons at room temperature in Co50Fe50/GaAs Schottky tunnel junctions
Tetsuya Uemura; Takafumi Akiho; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 99, 8, 082108 (3pp), Aug. 2011, [Peer-reviewed]
English, Scientific journal

Electrical detection of spin injection from Co50Fe50 into GaAs at room temperature
T. Uemura; M. Harada; T. Akiho; K.-i. Matsuda; M. Yamamoto
15th Int’l Conf. on Modulated Semiconductor Structures (MSS 15), Abstracts, vol.15, Tu-P-87, Jul. 2011, [Peer-reviewed]
English, International conference proceedings

Oscillations in spin-dependent tunneling resistances as a function of MgO barrier thickness in epitaxial magnetic tunnel junctions with Heusler alloy Co2MnSi electrodes
Y. Honda; S. Hirata; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
5th Int’l Workshop on Spin Currents, Abstracts, vol.5, p.136, P2-36, Jul. 2011, [Peer-reviewed]
English, International conference proceedings

Spin injection from Co50Fe50 into GaAs at room temperature
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto
5th Int’l Workshop on Spin Currents, Abstracts, vol.5, p.122, P2-22, Jul. 2011, [Peer-reviewed]
English, International conference proceedings

Spin-dependent tunneling characteristics of Heusler alloy/MgO heterostructures
M. Yamamoto; T. Uemura; K.-i. Matsuda
5th Int’l Workshop on Spin Currents, Abstracts, vol.5, p.41, CA-1, Jul. 2011, [Peer-reviewed], [Invited]
English, International conference proceedings

Suppression of in-plane tunneling anisotropic magnetoresistance effect in Co2MnSi/MgO/n-GaAs and CoFe/MgO/n-GaAs junctions by inserting a MgO barrier
Takafumi Akiho; Tetsuya Uemura; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 98, 23, 232109 (3pp), Jun. 2011, [Peer-reviewed]
English, Scientific journal

Epitaxial growth of Heusler alloy Co2MnSi/MgO heterostructures on Ge(001) substrates
Gui-fang Li; Tomoyuki Taira; Ken-ichi Matsuda; Masashi Arita; Tetsuya Uemura; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 98, 26, 262505 (3pp), Jun. 2011, [Peer-reviewed]
English, Scientific journal

Epitaxial growth of Heusler alloy Co2MnSi/MgO heterostructure on Ge(001) substrate
G.-f. Li; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Magnetics Conf. 2011 (INTERMAG 2011), Digest(USB Memory), HC-06, Apr. 2011, [Peer-reviewed]
English, International conference proceedings

Electrical injection and detection of spin-polarized electrons in an epitaxial Co50Fe50/n-GaAs junction
T. Uemura; M. Harada; T. Akiho; K.-i. Matsuda; M. Yamamoto
Int’l Magnetics Conf. 2011(INTERMAG 2011), Digests (USB Memory), BP-08, Apr. 2011, [Peer-reviewed]
English, International conference proceedings

Spin-dependent transport properties of Co2MnSi/MgO/n-GaAs tunnel junctions
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto
Int’l Magnetics Conf. 2011 (INTERMAG 2011), Digest(USB Memory), BP-03, Apr. 2011, [Peer-reviewed]
English, International conference proceedings

Influence of GaAs surface structure on tunneling anisotropic magnetoresistance and magnetocrystalline anisotropy in epitaxial Co50Fe50/n-GaAs junctions
Tetsuya Uemura; Masanobu Harada; Takafumi Akiho; Ken-ichi Matsuda; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 98, 10, 102503 (3pp), Mar. 2011, [Peer-reviewed]
English, Scientific journal

Creation and control of spin current using Co-based Heusler alloy
T, Uemura; M. Yamamoto
Materia Japan, vol.49, 12, pp. 566-569, 569, The Japan Institute of Metals and Materials, Dec. 2010, [Peer-reviewed], [Invited]
Japanese, Scientific journal

Fabrication and the transport properties of NbN/Co2Cr0.6Fe0.4Al/NbN lateral junctions
Satoshi Imai; Ken-ichi Matsuda; Takayuki Ishikawa; Tetsuya Uemura; Masafumi Yamamoto
PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 470, S851, S853, Dec. 2010, [Peer-reviewed]
English, Scientific journal

Highly spin-polarized tunneling characteristics at room temperature in magnetic tunnel junctions with a half-metallic Heusler-alloy spin source and a MgO barrier
H.-x. Liu; T. Taira; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
55th Annual Conf. on Magnetism & Magnetic Materials, Abstracts (CD-ROM), vol.55, pp.370-371, ET-11, Nov. 2010, [Peer-reviewed]
English, International conference proceedings

Giant oscillations of spin-dependent tunneling resistances as a function of MgO barrier thickness in fully epitaxial magnetic tunnel junctions of Co2Cr0.6Fe0.4Al/MgO/Co2Cr0.6Fe0.4Al
M. Yamamoto; T. Marukame; T. Ishikawa; T. Taira; K.-i. Matsuda; T. Uemura
55th Annual Conf. on Magnetism & Magnetic Materials, Abstracts (CD-ROM), vol.55, p.165, CB-01, Nov. 2010, [Peer-reviewed]
English, International conference proceedings

Giant tunnel magnetoresistance in half-metallic Co2MnSi-based fully epitaxial magnetic tunnel junctions
T. Taira; H.-x. Liu; S. Hirata; K.-i. Matsuda; T. Uemura; M. Yamamoto
55th Annual Conf. on Magnetism & Magnetic Materials, Abstracts (CD-ROM), vol.55, pp.118-119, BH-10, Nov. 2010, [Peer-reviewed]
English, International conference proceedings

Superconducting proximity effect of spin-triplet pairs in NbN/Co2Cr0.6Fe0.4Al/NbN junctions
K.-i. Matsuda; T. Uemura; M. Yamamoto
55th Annual Conf. on Magnetism & Magnetic Materials, Abstracts (CD-ROM), vol.55, p.28, AE-10, Nov. 2010, [Peer-reviewed]
English, International conference proceedings

Highly spin-polarized tunneling in Heusler-alloy-based magnetic tunnel junctions with a Co2MnSi upper electrode and a MgO barrier
H.-x. Liu; T. Taira; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
2010 Int’l Conf. on Solid State Devices and Materials, Extended Abstract (USB-MEMORY), pp.1122-1123, F-6-4, Sep. 2010, [Peer-reviewed]
English, International conference proceedings

Electrical detection of a non-local signal in Co2MnSi/MgO/n-GaAs tunnel junctions
M. Harada; T. Uemura; T. Akiho; K.-i. Matsuda; M. Yamamoto
6th Int’l Conf. on the Physics and Application of Spin Related Phenomena in Semiconductors (PASPS-VI),Abstracts, vol.6, pp.259-260, P2-46, Aug. 2010, [Peer-reviewed]
English, International conference proceedings

Internal electric field influence on tunneling anisotropic magnetoresistance in epitaxial ferromagnet/n-GaAs junctions
Tetsuya Uemura; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 96, 25, 252106 (3pp), Jun. 2010, [Peer-reviewed]
English, Scientific journal

Effect of defects in Heusler alloy thin films on spin-dependent tunnelling characteristics of Co2MnSi/MgO/Co2MnSi and Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions
Masafumi Yamamoto; Takayuki Ishikawa; Tomoyuki Taira; Gui-fang Li; Ken-ichi Matsuda; Tetsuya Uemura
JOURNAL OF PHYSICS-CONDENSED MATTER, 22, 16, 164212 (9pp), Apr. 2010, [Peer-reviewed]
English, Scientific journal

Giant oscillations in spin-dependent tunneling resistances as a function of barrier thickness in fully epitaxial magnetic tunnel junctions with a MgO barrier
Takao Marukame; Takayuki Ishikawa; Tomoyuki Taira; Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
PHYSICAL REVIEW B, 81, 13, 134432 (5pp), Apr. 2010, [Peer-reviewed]
English, Scientific journal

Effect of the Mn composition in Co2MnSi electrodes on tunnel magnetoresistance characteristics of Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
T. Ishikawa; H.-x. Liu; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
11th Joint MMM/Intermag Conf., Digest (CD-ROM), vol.11, p.1888, HH-04, Jan. 2010, [Peer-reviewed]
English, International conference proceedings

Strong bias-voltage dependence of tunneling anisotropic magneto-resistance in epitaxial ferromagnet/n-GaAs junctions
T. Uemura; M. Harada; K.-i. Matsuda; M. Yamamoto
11th Joint MMM/Intermag Conf., Digests (CD-ROM), vol.11, p.1225, EU-17, Jan. 2010, [Peer-reviewed]
English, International conference proceedings

Effect of defects in Heusler alloy thin films on spin-dependent tunnelling characteristics of Co2MnSi/MgO/Co2MnSi and Co 2MnGe/MgO/Co2MnGe magnetic tunnel junctions
Masafumi Yamamoto; Takayuki Ishikawa; Tomoyuki Taira; Gui-Fang Li; Ken-Ichi Matsuda; Tetsuya Uemura
Journal of Physics Condensed Matter, 22, 16, p.1192, ET-03, 2010, [Peer-reviewed]
English, Scientific journal

Influence of film composition in Co2MnSi electrodes on tunnel magnetoresistance characteristics of Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
Takayuki Ishikawa; Hong-xi Liu; Tomoyuki Taira; Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 95, 23, 232512 (3pp), Dec. 2009, [Peer-reviewed]
English, Scientific journal

Tunneling Magnetoresistance Simulation Used to Detect Domain-Wall Structures and Their Motion in a Ferromagnetic Wire
Keisuke Sawada; Tetsuya Uemura; Masahiro Masuda; Ken-ichi Matsuda; Masafumi Yamamoto
IEEE TRANSACTIONS ON MAGNETICS, 45, 10, 3780, 3783, Oct. 2009, [Peer-reviewed]
English, Scientific journal

Fabrication and Transport Properties of NbN/Co2Cr0.6Fe0.4Al/NbN Lateral Junctions
S. Imai; K.-i. Matsuda; T. Ishikawa; T. Uemura; M. Yamamoto
9th Int’l Conf. on Materials and Mechanisms of Superconductivity (M2S-IX) (USB Memory), vol.9, PS-G-589, Sep. 2009, [Peer-reviewed]
English, International conference proceedings

Tunneling anisotropic magneto-resistance in an epitaxial Co2MnSi/n-GaAs junction
M. Harada; T. Uemura; Y. Imai; K.-i. Matsuda; M. Yamamoto
The 14th Int’l Conf. on Modulated Semiconductor Structures (MSS-14), Abstract, vol.14, p.195, M5e, Jul. 2009, [Peer-reviewed]
English, International conference proceedings

Spin-dependent tunneling characteristics of fully epitaxial Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions
T. Taira; S. Hirata; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
20th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS2009), Abstracts, p.381, P-We30, Jul. 2009, [Peer-reviewed]
English, International conference proceedings

Tunneling spectroscopy of magnetic tunnel junctions with Heusler alloy Co2MnGe electrodes and a MgO barrier
S. Hirata; T. Taira; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2009), Abstracts, p.54, Mo-A-5.4-07, Jul. 2009, [Peer-reviewed]
English, International conference proceedings

Spin-dependent electronic structure of Heusler alloy Co2MnSi upper electrodes in magnetic tunnel junctions
T. Ishikawa; N. Itabashi; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2009), Abstracts, p.54, Mo-A-5.4-05, Jul. 2009, [Peer-reviewed]
English, International conference proceedings

Transport properties of a junction consisting of two NbN electrodes coupled by a Co-based Heusler alloy Co2Cr0.6Fe0.4Al channel
K.-i. Matsuda; S. Imai; T. Ishikawa; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2009), Abstracts, p.55, Mo-A-5.4-13, Jul. 2009, [Peer-reviewed]
English, International conference proceedings

Spin-dependent tunneling in half-metallic Heusler alloy-based magnetic tunnel junctions with a MgO barrier
M. Yamamoto; T. Ishikawa; T. Taira; T. Marukame; K.-i. Matsuda; T. Uemura
Int’l Conf. on Magnetism (ICM2009), Abstracts, p.155, Tu-JPH6-01, Jul. 2009, [Peer-reviewed]
English, International conference proceedings

Double magnetic tunnel junctions with cross-magnetization configurations for electrical detection of domain-wall structures
Tetsuya Uemura; Keisuke Sawada; Ken-ichi Matsuda; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 95, 1, 012502 (3pp), Jul. 2009, [Peer-reviewed]
English, Scientific journal

Simulation of tunneling magnetoresistance used to detect domain-wall structure and motion in a ferromagnetic wire
K. Sawada; T. Uemura; M. Masuda; K.-i. Matsuda; M. Yamamoto
IEEE Int’l Magnetics Conf. 2009, Digests (CD-ROM), BD-07, May 2009, [Peer-reviewed]
English, International conference proceedings

Tunneling anisotropic magnetoresistance in epitaxial CoFe/n-GaAs junctions
Tetsuya Uemura; Yosuke Imai; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 94, 18, BQ-13, May 2009, [Peer-reviewed]
English, Scientific journal

Tunneling anisotropic magnetoresistance in epitaxial CoFe/n-GaAs junctions
Tetsuya Uemura; Yosuke Imai; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 94, 18, 182502 (3pp), May 2009, [Peer-reviewed]
English, Scientific journal

Half-metallic electronic structure of Co2MnSi electrodes in fully epitaxial Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions investigated by tunneling spectroscopy (invited)
Takayuki Ishikawa; Naoki Itabashi; Tomoyuki Taira; Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
JOURNAL OF APPLIED PHYSICS, 105, 7, 07B110 (6pp), Apr. 2009, [Peer-reviewed]
English, Scientific journal

Hard x-ray photoelectron spectroscopy of buried Heusler compounds
Siham Ouardi; Benjamin Balke; Andrei Gloskovskii; Gerhard H. Fecher; Claudia Felser; Gerd Schoenhense; Takayuki Ishikawa; Tetsuya Uemura; Masafumi Yamamoto; Hiroaki Sukegawa; Wenhong Wang; Koichiro Inomata; Yoshiyuki Yamashita; Hideki Yoshikawa; Shigenori Ueda; Keisuke Kobayashi
JOURNAL OF PHYSICS D-APPLIED PHYSICS, 42, 8, 084010 (7 pp), Apr. 2009, [Peer-reviewed]
English, Scientific journal

Spin-dependent tunnelling characteristics of fully epitaxial magnetic tunnel junctions with a Heusler alloy Co2MnGe thin film and a MgO barrier
Tomoyuki Taira; Takayuki Ishikawa; Naoki Itabashi; Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
JOURNAL OF PHYSICS D-APPLIED PHYSICS, 42, 8, 084015 (9 pp), Apr. 2009, [Peer-reviewed]
English, Scientific journal

Critical role of interface states for spin-dependent tunneling in half-metallic Co2MnSi-based magnetic tunnel junctions investigated by tunneling spectroscopy
Takayuki Ishikawa; Naoki Itabashi; Tomoyuki Taira; Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 94, 9, 092503 (3pp), Mar. 2009, [Peer-reviewed]
English, Scientific journal

Influence of annealing on spin-dependent tunneling characteristics of fully epitaxial Co2MnGe/MgO/Co50Fe50 magnetic tunnel junctions
Tomoyuki Taira; Takayuki Ishikawa; Naoki Itabashi; Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 94, 7, 072510 (3pp), Feb. 2009, [Peer-reviewed]
English, Scientific journal

Transport properties of Nb/PdNi bilayers and Nb/PdNi/Nb Josephson junctions
K. -i. Matsuda; Y. Akimoto; T. Uemura; M. Yamamoto
25TH INTERNATIONAL CONFERENCE ON LOW TEMPERATURE PHYSICS (LT25), PART 5, 150, p.25, PB-Th118, 2009, [Peer-reviewed]
English, International conference proceedings

Transport properties of Nb/PdNi bilayers and Nb/PdNi/Nb Josephson junctions
K. -i. Matsuda; Y. Akimoto; T. Uemura; M. Yamamoto
25TH INTERNATIONAL CONFERENCE ON LOW TEMPERATURE PHYSICS (LT25), PART 5, 150, 052155 (4pp), 2009, [Peer-reviewed]
English, International conference proceedings

Tunnel magnetoresistance characteristics of post-deposition-annealed Co2MnGe/MgO/CoFe tunnel junctions
T. Taira; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
2008 Material Research Society (MRS) Fall Meeting, Abstracts(CD-ROM), L2.1, Dec. 2008, [Peer-reviewed]
English, International conference proceedings

Tunneling conductance characteristics for Co2Cr0.6Fe0.4Al/MgO/Co2Cr0.6Fe0.4Al magnetic tunnel junctions
N. Itabashi; T. Ishikawa; K. Yonemura; K.-i. Matsuda; T. Uemura; M. Yamamoto
2008 Material Research Society (MRS) Fall Meeting, Abstracts (CD-ROM), L2.10, Dec. 2008, [Peer-reviewed]
English, International conference proceedings

Tunneling spectroscopy of fully epitaxial Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
T. Ishikawa; N. Itabashi; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
2008 Material Research Society (MRS) Fall Meeting, Abstracts (CD-ROM), L5.1, Dec. 2008, [Peer-reviewed]
English, International conference proceedings

Three-valued magnetic tunnel junction for nonvolatile ternary content addressable memory application
Tetsuya Uemura; Masafumi Yamamoto
JOURNAL OF APPLIED PHYSICS, 104, 12, 123911 (5pp), Dec. 2008, [Peer-reviewed]
English, Scientific journal

Half-metallic electronic structure of Co2MnSi electrodes proved by tunneling spectroscopy
T. Ishikawa; N. Itabashi; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
53rd Magnetism and Magnetic Materials Conf., Abstracts(CD-ROM), vol.53, p.232, DD-07, Nov. 2008, [Peer-reviewed]
English, International conference proceedings

Spin-dependent tunneling characteristics of Co2MnGe/MgO/CoFe tunnel junctions
T. Taira; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
53rd Magnetism and Magnetic Materials Conf., Abstracts (CD-ROM), vol.53, p.230, DD-02, Nov. 2008, [Peer-reviewed]
English, International conference proceedings

Tunneling spectroscopy of Co2Cr0.6Fe0.4Al/MgO/CoFe magnetic tunnel junctions
K. Yonemura; T. Ishikawa; N. Itabashi; K.-i. Matsuda; T. Uemura; M. Yamamoto
53rd Magnetism and Magnetic Materials Conf., Abstracts (CD-ROM), vol.53, p.301, ED-07, Nov. 2008, [Peer-reviewed]
English, International conference proceedings

Spin-dependent electronic structures of Co2Cr0.6Fe0.4Al electrodes investigated through tunneling spectroscopy
N. Itabashi; T. Ishikawa; K. Yonemura; K.-i. Matsuda; T. Uemura; M. Yamamoto
53rd Magnetism and Magnetic Materials Conf., Abstracts (CD-ROM), vol.53, pp. 480-481, GT-03, Nov. 2008, [Peer-reviewed]
English, International conference proceedings

Fabrication and Characterization of Fully Epitaxial Magnetic Tunnel Junction Field Sensors Using a Co2MnSi Thin Film
Masahiro Masuda; Tetsuya Uemura; Ken-ichi Matsuda; Masafumi Yamamoto
IEEE TRANSACTIONS ON MAGNETICS, 44, 11, 3996, 3998, Nov. 2008, [Peer-reviewed]
English, Scientific journal

Spin-dependent tunneling spectroscopy of fully epitaxial magnetic tunnel junctions with Heusler alloy Co2Cr0:6Fe0:4Al electrodes and a MgO barrier
N. Itabashi; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
25th Int’l Conf. on Low Temp. Physics, Official Conf. Book, vol.25, p.258, PD-Mo244, Aug. 2008, [Peer-reviewed]
English, International conference proceedings

Fabrication and characterization of magnetic tunnel junction field sensors with a Co2MnSi thin film
M. Masuda; T. Uemura; K.-i. Matsuda; M. Yamamoto
IEEE Int'l Magnetics Conf. Europe 2008,Technical Digests (CD-ROM), p.269, BD-04, May 2008, [Peer-reviewed]
English, International conference proceedings

Spin-dependent tunneling conductance in fully epitaxial Co2MnSi/MgO/Co2MnsI tunnel junctions
T. Ishikawa; N. Itabashi; K. Matsuda; T. Uemura; M. Yamamoto
IEEE Int'l Magnetics Conf. Europe 2008,Technical Digests (CD-ROM), p.33, AC-07, May 2008, [Peer-reviewed]
English, International conference proceedings

Structural, magnetic, and electrical properties of Co2MnSi/MgO/n-GaAs tunnel junctions
S. Kawagishi; T. Uemura; Y. Imai; K. -I. Matsuda; M. Yamamoto
JOURNAL OF APPLIED PHYSICS, 103, 7, 07A703 (3pp), Apr. 2008, [Peer-reviewed]
English, Scientific journal

Magnetic and transport properties of superconductor/ferromagnet bilayer microbridges
Ken-ichi Matsuda; Yosuke Akimoto; Tetsuya Uemura; Masafumi Yamamoto
JOURNAL OF APPLIED PHYSICS, 103, 7, 07C711 (3pp), Apr. 2008, [Peer-reviewed]
English, Scientific journal

Electronic and magnetic properties of Heusler alloy Co2MnSi epitaxial ultrathin films facing a MgO barrier studied by x-ray magnetic circular dichroism
Toshiaki Saito; Toshikazu Katayama; Ai Emura; Noa Sumida; Nanae Matsuoka; Takayuki Ishikawa; Tetsuya Uemura; Masafumi Yamamoto; Daisuke Asakura; Tsuneharu Koide
JOURNAL OF APPLIED PHYSICS, 103, 7, 07D712 (3pp), Apr. 2008, [Peer-reviewed]
English, Scientific journal

Fabrication of fully epitaxial Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
Takayuki Ishikawa; Shinya Hakamata; Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
JOURNAL OF APPLIED PHYSICS, 103, 7, 07A919 (3pp), Apr. 2008, [Peer-reviewed]
English, Scientific journal

Epitaxial growth and characterization of Co2MnSi thin films on GaAs with MgO interlayer
Tetsuya Uemura; Yosuke Imai; Saori Kawagishi; Ken-ichi Matsuda; Masafumi Yamamoto
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, 40, 6, 2025, 2027, Apr. 2008, [Peer-reviewed]
English, Scientific journal

Heusler alloy-based fully epitaxial magnetic tunnel junctions with a MgO barrier
M. Yamamoto; T. Uemura; K.-i. Matsuda
2008 RCIQE Int’l Seminar on “Advanced Semiconductor Materials and Devices”, Collected Abstracts, pp.29-37, Mar. 2008, [Invited]
English

Magnetic and transport properties of superconductor/ferromagnet bilayer microbridges
Ken-Ichi Matsuda; Yosuke Akimoto; Tetsuya Uemura; Masafumi Yamamoto
Journal of Applied Physics, 103, 7, p.489, HQ-10, 2008, [Peer-reviewed]
English, International conference proceedings

Electronic and magnetic properties of Heusler alloy Co2MnSi epitaxial ultrathin films facing a MgO barrier studied by x-ray magnetic circular dichroism
Toshiaki Saito; Toshikazu Katayama; Ai Emura; Noa Sumida; Nanae Matsuoka; Takayuki Ishikawa; Tetsuya Uemura; Masafumi Yamamoto; Daisuke Asakura; Tsuneharu Koide
Journal of Applied Physics, 103, 7, p.116, BQ-06, 2008, [Peer-reviewed]
English, International conference proceedings

Highly spin-polarized tunneling in fully epitaxial magnetic tunnel junctions with a Co-based full-Heusler alloy thin film and a MgO barrier
Masafumi Yamamoto; Taluto Marukame; Takayuki Ishikawa; Ken-ichi Matsuda; Tetsuya Uemura
ADVANCES IN SOLID STATE PHYSICS, 47, 105, 116, 2008, [Peer-reviewed]
English, International conference proceedings

Production of bacterial cellulose with well oriented fibril on PDMS substrate
Ananda Putra; Akira Kakugo; Hidentitsu Furukawa; Jian P. Gong; Yoshihito Osada; Tetsuya Uemura; Masafumi Yamamoto
POLYMER JOURNAL, 40, 2, 137, 142, 2008, [Peer-reviewed]
English, Scientific journal

Electrical characterization of epitaxial Co2MnSi/MgO/n-GaAs tunnel junctions
S. Kawagishi; T. Uemura; Y. Imai; K.-i. Matsuda; M. Yamamoto
52nd Magnetism and Magnetic Materials Conf., Abstracts, vol.52, p.38, AG-09, Nov. 2007, [Peer-reviewed]
English, International conference proceedings

Spin-dependent tunneling in fully epitaxial Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
T. Ishikawa; S. Hakamata; K.-i. Matsuda; T. Uemura; M. Yamamoto
52nd Magnetism and Magnetic Materials Conf., Abstracts, vol.52, p.13, AB-07, Nov. 2007, [Peer-reviewed]
English, International conference proceedings

Oscillations in tunneling resistance as a function of MgO barrier thickness in fully epitaxial magnetic tunnel junctions of Co2Cr0.6Fe0.4Al/MgO/Co50Fe50
M. Yamamoto; T. Marukame; T. Ishikawa; K. Matsuda; T. Uemura
52nd Magnetism and Magnetic Materials Conf., Abstracts, vol.52, p.14, AB-11, Nov. 2007, [Peer-reviewed]
English, International conference proceedings

Highly spin-polarized tunneling in Heusler alloy-based fully epitaxial magnetic tunnel junctions with a MgO tunnel barrier
M. Yamamoto; T. Marukame; T. Ishikawa; K. Matsuda; T. Uemura
52nd Magnetism and Magnetic Materials Conf., Abstracts, vol.52, p.204, DB-01, Nov. 2007, [Peer-reviewed]
English, International conference proceedings

Epitaxial growth and characterization of Co2MnSi thin films on GaAs with MgO interlayer
T. Uemura; T. Yano; Y. Imai; K. Matsuda; M. Yamamoto
The 13th Int’l Conf. on Modulated Semiconductor Structures (MSS13), Abstracts, vol.13, pp.172-173, Jul. 2007, [Peer-reviewed]
English, International conference proceedings

Fabrication of Epitaxial Magnetic Tunnel Junctions with a Co2Cr0.6Fe0.4Al Thin Film and Their Tunnel Magnetoresistance Characteristics
T. Marukame; T. Ishikawa; S. Hakamata; K.-i. Matsuda; T. Uemura; M. Yamamoto
J. Magn. Soc. Jpn., vol.31, no. 4, pp. 344-350, 350, The Magnetics Society of Japan, Jul. 2007, [Peer-reviewed]
English, Scientific journal, Fully epitaxial magnetic tunnel junctions (MTJs) were fabricated with a full-Heusler alloy Co₂Cr_0.6Fe_0.4Al (CCFA) thin film and a MgO tunnel barrier. Cross-sectional high-resolution transmission electron microscope observations clearly showed that all layers of CCFA/MgO/Co₅₀Fe₅₀ MTJ layer structures were grown epitaxially and were single-crystalline. The fully epitaxial CCFA/MgO/Co₅₀Fe₅₀ MTJs, where we used the difference in the coercive forces to form the antiparallel magnetization configurations between the lower and upper electrodes, demonstrated high tunnel magnetoresistance (TMR) ratios of 90% at room temperature (RT) and 240% at 4.2 K. This result suggested that a CCFA film composition close to the stoichiometric one is essential for obtaining high spin polarizations in CCFA thin films. The fully epitaxial CCFA/MgO/Co₅₀Fe₅₀ MTJs with exchange-biasing, where a Co₅₀Fe₅₀ upper electrode was used in a synthetic ferrimagnetic Co₅₀Fe₅₀/Ru/Co₉₀Fe₁₀ trilayer exchange-biased with an IrMn layer through the Co₉₀Fe₁₀/IrMn interface, exhibited high TMR ratios of 109% at RT and 317% at 4.2 K. From the obtained TMR ratio of 317% at 4.2 K, a high tunneling spin polarization of 0.88 at 4.2 K was estimated for epitaxial CCFA films with the B2 structure. These results confirm the promise of an epitaxial MTJ using a Co-based full-Heusler alloy as a key device structure for utilizing the potentially high spin polarization of this material system.

Structural and magnetic properties Of Co2Cr0.6Fe0.4Al thin films epitaxially grown on GaAs substrates with MgO interlayer
T. Uemura; T. Yano; K.-I. Matsuda
THIN SOLID FILMS, 515, 20-21, 8013, 8016, Jul. 2007, [Peer-reviewed]
English, Scientific journal

Magnetic and transport properties of Nb/PdNi bilayers
Ken-ichi Matsuda; Hirotaka Niwa; Yosuke Akimoto; Tetsuya Uemura; Masafumi Yamamoto
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 17, 2, 3529, 3532, Jun. 2007, [Peer-reviewed]
English, Scientific journal

Fabrication of fully epitaxial Co2Cr0.6Fe0.4Al/MgO/Co2Cr0.6Fe0.4Al magnetic tunnel junctions
T. Marukame; T. Ishikawa; S. Hakamata; K-I Matsuda; T. Uemura; M. Yamamoto
IEEE TRANSACTIONS ON MAGNETICS, 43, 6, 2782, 2784, Jun. 2007, [Peer-reviewed]
English, Scientific journal

Four-state magnetoresistance in epitaxial CoFe-based magnetic tunnel junctions
Tetsuya Uemura; Takao Marukame; Ken-ichi Matsuda; Masafumi Yamamoto
IEEE TRANSACTIONS ON MAGNETICS, 43, 6, 2791, 2793, Jun. 2007, [Peer-reviewed]
English, Scientific journal

Four-state Magnetic Random Access Memory and Ternary Content Addressable Memory using CoFe-based Magnetic Tunnel Junctions
T. Uemura; T. Marukame; K.-i. Matsuda; M. Yamamoto
37th Int’l Symposium on Multiple-Valued Logic, CD-ROM, vol.37, pp.49-1 - 49-6, May 2007, [Peer-reviewed]
English, International conference proceedings

Improved tunnel magnetoresistance characteristics of magnetic tunnel junctions with a Heusler alloy thin film of Co2MnGe and a MgO tunnel barrier
Shinya Hakamata; Takayuki Ishikawa; Takao Marukame; Ken-ichi Matsuda; Tetsuya Uemura; Masashi Arita; Masafumi Yamamoto
JOURNAL OF APPLIED PHYSICS, 101, 9, 09J513 (3pp), May 2007, [Peer-reviewed]
English, Scientific journal

Highly spin-polarized tunneling in fully epitaxial magnetic tunnel junctions with a Co-based full-Heusler alloy thin film and a MgO barrier
M. Yamamoto; T. Marukame; T. Ishikawa; K. Matsuda; T. Uemura
71stAnnual Meeting 2007 of the German Physical Society and DPG-Spring Meeting of the Division Condensed Matter, Verhandlungen, vol.71, p.487, MA22.2, Mar. 2007, [Peer-reviewed]
English, International conference proceedings

Effect of a MgO interlayer on the structural and magnetic properties of Co2Cr0.6Fe0.4Al thin films epitaxially grown on GaAs substrates
T. Yano; T. Uemura; K. -i. Matsuda; M. Yamamoto
JOURNAL OF APPLIED PHYSICS, 101, 6, 063904 (4pp), Mar. 2007, [Peer-reviewed]
English, Scientific journal

Analysis of magnetic anisotropy for Co2Cr0.6Fe0.4Al thin films epitaxially grown on GaAs
Tetsuya Uemura; Toshifumi Yano; Ken-ichi Matsuda; Masafumi Yamamoto
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 310, 2, E696, E698, Mar. 2007, [Peer-reviewed]
English, Scientific journal

Fabrication of fully epitaxial magnetic tunnel junctions with a Co2MnSi thin film and a MgO tunnel barrier
H. Kijima; T. Ishikawa; T. Marukame; K.-I. Matsuda; T. Uemura; M. Yamamoto
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 310, 2, 2006, 2008, Mar. 2007, [Peer-reviewed]
English, Scientific journal

Spin-dependent transport properties of fully epitaxial Co2MnSi/MgO/Co50Fe50 tunnel junctions
T. Marukame; H. Kijima; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 310, 2, 1946, 1948, Mar. 2007, [Peer-reviewed]
English, Scientific journal

Fabrication of exchange-biased epitaxial magnetic tunnel junctions with a Heusler alloy Co2Cr0.6Fe0.4Al thin film
T. Ishikawa; T. Marukame; S. Hakamata; K.-i. Matsuda; T. Uemura; M. Yamamoto
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 310, 2, 1897, 1899, Mar. 2007, [Peer-reviewed]
English, Scientific journal

Spin-dependent tunneling in fully epitaxial magnetic tunnel junctions with a Heusler alloy thin film and a MgO barrier
M. Yamamoto; T. Uemura; K.-i. Matsuda
The 2nd RIEC Int’l Workshop on Spintronics?MgO-based Magnetic Tunnel Junctions?, Abstracts, vol.2, Feb. 2007, [Invited]
English

Dependence of magnetoresistance characteristics of magnetic tunnel junctions with a Heusler alloy thin film of either Co2MnGe or Co2MnSi on film composition
S. Hakamata; T. Ishikawa; T. Marukame; K. Matsuda; T. Uemura; M. Arita; M. Yamamoto
10th Joint MMM/Intermag Conf., Abstracts, vol.10, p.443, GD-10, Jan. 2007, [Peer-reviewed]
English, International conference proceedings

Fabrication of fully epitaxial Co2Cr0.6Fe0.4Al/MgO/Co2Cr0.6Fe0.4Al
T. Marukame; T. Ishikawa; S. Hakamata; K. Matsuda; T. Uemura; M. Yamamoto
10th Joint MMM/Intermag Conf., Abstracts, vol.10, p.209, DD-07, Jan. 2007, [Peer-reviewed]
English, International conference proceedings

Four-state magnetoresistance in epitaxial CoFe-based magnetic tunnel junction
T. Uemura; T. Marukame; K. Matsuda; M. Yamamoto
10th Joint MMM/Intermag Conf., Abstracts, vol.10, p.47, AP-08, Jan. 2007, [Peer-reviewed]
English, International conference proceedings

Highly spin-polarized tunneling in fully epitaxial Co2Cr0.6Fe0.4Al/MgO/Co50Fe50 magnetic tunnel junctions with exchange biasing
Takao Marukame; Takayuki Ishikawa; Shinya Hakamata; Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 90, 1, 012508 (3pp), Jan. 2007, [Peer-reviewed]
English, Scientific journal

Spin-dependent tunneling characteristics of fully epitaxial magnetic tunneling junctions with a full-Heusler alloy Co2MnSi thin film and a MgO tunnel barrier
T. Ishikawa; T. Marukame; H. Kijima; K. -I. Matsuda; T. Uemura; M. Arita; M. Yamamoto
APPLIED PHYSICS LETTERS, 89, 19, 192505 (3pp), Nov. 2006, [Peer-reviewed]
English, Scientific journal

Exchange bias effect in full-Heusler alloy Co2Cr0.6Fe0.4Al epitaxial thin films
T. Ishikawa; T. Marukame; K. -i Matsuda; T. Uemura; M. Yamamoto
IEEE TRANSACTIONS ON MAGNETICS, 42, 10, 3002, 3004, Oct. 2006, [Peer-reviewed]
English, Scientific journal

Epitaxial growth of full-Heusler alloy Co2MnSi thin films on MgO-buffered MgO substrates
H. Kijima; T. Ishikawa; T. Marukame; H. Koyama; K. Matsuda; T. Uemura; M. Yamamoto
IEEE TRANSACTIONS ON MAGNETICS, 42, 10, 2688, 2690, Oct. 2006, [Peer-reviewed]
English, Scientific journal

Highly spin-polarized tunneling in fully epitaxial magnetic tunnel junctions using full-Heusler alloy Co2Cr0.6Fe0.4Al thin film and MgO tunnel barrier
T. Marukame; T. Ishikawa; W. Sekine; K. Matsuda; T. Uemura; M. Yamamoto
IEEE TRANSACTIONS ON MAGNETICS, 42, 10, 2652, 2654, Oct. 2006, [Peer-reviewed]
English, Scientific journal

Magnetic and Transport Properties of Nb/PdNi Bilayers
K.-i. Matsuda; H. Niwa; Y. Akimoto; T. Uemura; M. Yamamoto
IEEE Int’l Conf. on Appl. Supercond., CD-ROM, 2MM04, Aug. 2006, [Peer-reviewed]
English, International conference proceedings

Fabrication of exchange-biased epitaxial magnetic tunnel junctions with a Co-based full-Heusler alloy thin film
T. Ishikawa; S. Hakamata; T. Marukame; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2006), Abstracts, p.582, Aug. 2006, [Peer-reviewed]
English, International conference proceedings

Analysis of magnetic anisotropy for Co2Cr0.6Fe0.4Al thin films epitaxially grown on GaAs
T. Uemura; T. Yano; K.-i. Matsuda; M. Yamamoto
Int’l Conf. on Magnetism (ICM2006), Abstracts, p.313, DD-07, Aug. 2006, [Peer-reviewed]
English, International conference proceedings

Spin-dependent transport properties of fully epitaxial Co2MnSi/MgO/CoFe tunnel junctions
T. Marukame; H. Kijima; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2006), Abstracts, p.198, Aug. 2006, [Peer-reviewed]
English, International conference proceedings

Fabrication of fully epitaxial magnetic tunnel junctions using Co2MnSi thin film and MgO tunnel barrier
H. Kijima; T. Ishikawa; T. Marukame; K. -i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2006), Abstracts, p.30, Aug. 2006, [Peer-reviewed]
English, International conference proceedings

MgO barrier thickness dependence of tunnel magnetoresistance in fully epitaxial magnetic tunnel junctions with Co2Cr0.6Fe0.4Al thin film
T. Marukame; T. Ishikawa; H. Kijima; K.?i. Matsuda; T. Uemura; M. Yamamoto
19th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS 2006), Colloquium Digest, vol.19, pp.448-449, P-12-9, Aug. 2006, [Peer-reviewed]
English, International conference proceedings

Spin-dependent conductance versus voltage characteristics of fully epitaxial magnetic tunnel junctions with a Co-based full-Heusler alloy thin film and a MgO barrier
M. Yamamoto; T. Marukame; K.?i. Matsuda; T. Uemura
19th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS 2006), Colloquium Digest, vol.19, pp.440-441, Aug. 2006, [Peer-reviewed]
English, International conference proceedings

Structural and magnetic properties of Co2Cr0.6Fe0.4Al thin films epitaxially grown on GaAs with and without MgO interlayer
T. Uemura; T. Yano; K.?i. Matsuda; M. Yamamoto
19th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS 2006), Colloquium Digest, vol.19, pp.20-21, DD-07, Aug. 2006, [Peer-reviewed]
English, International conference proceedings

High tunnel magnetoresistance in fully epitaxial magnetic tunnel junctions with a full-Heusler alloy Co2Cr0.6Fe0.4Al thin film
Takao Marukame; Takayuki Ishikawa; Ken-Ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
APPLIED PHYSICS LETTERS, 88, 26, 262503 (3pp), Jun. 2006, [Peer-reviewed]
English, Scientific journal

Analysis of anisotropic tunnel magneto-resistance of (Ga,Mn)As/AlAs/(Ga,Mn)As magnetic tunnel junction
T Uemura; R Miura; T Yamazuki; T Sone; KI Matsuda; M Yamamoto
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, 32, 1-2, 383, 386, May 2006, [Peer-reviewed]
English, Scientific journal

Tunnel magnetoresistance in epitaxial magnetic tunnel junctions using full-Heusler alloy Co2MnGe thin film and MgO tunnel barrier
T Marukame; T Ishikawa; K Matsuda; T Uemura; M Yamamoto
JOURNAL OF APPLIED PHYSICS, 99, 8, 08A904 (3pp), Apr. 2006, [Peer-reviewed]
English, Scientific journal

Structural and magnetic properties of epitaxially grown full-Heusler alloy Co2MnGe thin films deposited using magnetron sputtering
T Ishikawa; T Marukame; K Matsuda; T Uemura; M Arita; M Yamamoto
JOURNAL OF APPLIED PHYSICS, 99, 8, 08J110 (3pp), Apr. 2006, [Peer-reviewed]
English, Scientific journal

Fabrication of fully epitaxial magnetic tunnel junctions using cobalt-based full-Heusler alloy thin film and their tunnel magnetoresistance characteristics
M Yamamoto; T Marukame; T Ishikawa; K Matsuda; T Uemura; M Arita
JOURNAL OF PHYSICS D-APPLIED PHYSICS, 39, 5, 824, 833, Mar. 2006, [Peer-reviewed]
English, Scientific journal

Epitaxially grown full-Heusler alloy thin films and application to magnetic tunnel junctions
M. Yamamoto; T. Uemura; K.-i. Matsuda
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Collected Papers, vol.3, pp.79-92, Feb. 2006, [Invited]
English

Epitaxial growth of full-Heusler alloy Co2MnSi thin films on MgO-buffered MgO sub-strates
H. Kijima; T. Ishikawa; T. Marukame; H. Koyama; K. Matsuda; T. Uemura; M. Yamamoto
INTERMAG 2006 - IEEE International Magnetics Conference, vol.19, 377, 2006, [Peer-reviewed]
English, International conference proceedings

Highly spin-polarized tunneling in fully epitaxial magnetic tunnel junctions using full-Heusler alloy Co2Cr0.6Fe 0.4Al thin film and MgO tunnel barrier
T. Marukame; T. Ishikawa; H. Kijima; W. Sekine; K. Matsuda; T. Uemura; M. Yamamoto
INTERMAG 2006 - IEEE International Magnetics Conference, 723, 2006, [Peer-reviewed]
English, International conference proceedings

Exchange bias effect on full-Heusler alloy Co2Cr 0.6Fe0.4Al epitaxial thin films
T. Ishikawa; T. Marukame; H. Niwa; K. Matsuda; T. Uemura; M. Yamamoto
INTERMAG 2006 - IEEE International Magnetics Conference, 577, 2006, [Peer-reviewed]
English, International conference proceedings

Epitaxial growth of full-Heusler alloy Co2MnSi thin films on MgO-buffered MgO sub-strates
H. Kijima; T. Ishikawa; T. Marukame; H. Koyama; K. Matsuda; T. Uemura; M. Yamamoto
INTERMAG 2006 - IEEE International Magnetics Conference, 377, 2006, [Peer-reviewed]
English, International conference proceedings

Epitaxial growth Of C02Cr0.6Fe0.4Al Heusler alloy thin films on MgO (001) substrates by magnetron sputtering
K Matsuda; T Kasahara; T Marukame; T Uemura; M Yamamoto
JOURNAL OF CRYSTAL GROWTH, 286, 2, 389, 393, Jan. 2006, [Peer-reviewed]
English, Scientific journal

Structural and magnetic properties of epitaxially grown full-Heusler alloy Co2MnGe thin films deposited using magnetron sputtering
T. Ishikawa; T. Marukame; K. ?i. Matsuda; T. Uemura; M. Yamamoto
50th Annual Conf. on Magnetism & Magnetic Materials, Abstract, vol.50, p.370, GD-04, Oct. 2005, [Peer-reviewed]
English, International conference proceedings

Tunnel magnetoresistance in epitaxial magnetic tunnel junctions using full-Heusler alloy Co2MnGe thin film and MgO tunnel barrier
T. Marukame; T. Ishikawa; K. ?i. Matsuda; T. Uemura; M. Yamamoto
50th Annual Conf. on Magnetism & Magnetic Materials, Abstract, vol.50, p.18, AC-09, Oct. 2005, [Peer-reviewed]
English, International conference proceedings

High tunnel magnetoresistance in epitaxial Co2Cr0.6Fe0.4Al/MgO/CoFe tunnel junctions
T Marukame; T Kasahara; KI Matsuda; T Uemura; A Yamamoto
IEEE TRANSACTIONS ON MAGNETICS, 41, 10, 2603, 2605, Oct. 2005, [Peer-reviewed]
English, Scientific journal

Epitaxial Growth of Heusler Alloy Co2Cr0.6Fe0.4Al Thin Films by Magnetron Sputtering
T. Kasahara; K.-i. Matsuda; T. Marukame; T. Uemura; M. Yamamoto
J. The Magnetics Society of Japan, vol.29, no. 9, pp. 895-899, 899, The Magnetics Society of Japan, Sep. 2005, [Peer-reviewed]
English, International conference proceedings, Epitaxial Co₂Cr_0.6Fe_0.4Al full-Heusler alloy thin films, featuring excellent surface flatness of less than 0.2 nm rms in roughness, were grown on MgO(001) substrates by magnetron sputtering deposition at room temperature and subsequent annealing at temperatures ranging from 500 to 600 °C . The ferromagnetic properties of the films in terms of Curie temperature and saturation magnetization were also improved by annealing process.

Epitaxial growth of Fe/MgO/Fe heterostructures on SrTiO3(001) substrates by magnetron sputtering
T Marukame; K Matsuda; T Uemura; M Yamamoto
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 44, 8, 6012, 6015, Aug. 2005, [Peer-reviewed]
English, Scientific journal

Analysis of anisotropic tunnel magneto-resistance of GaMnAs/AlAs/GaMnAs magnetic tunnel junction
T. Uemura; R. Miura; T. Sone; K. Matsuda; M. Yamamoto
12th Int’l Conf. on Modulated Semiconductors (MSS 12), Abstract, vol12, THU-PC1, Jul. 2005, [Peer-reviewed]
English, International conference proceedings

High Tunnel Magnetoresistance in Epitaxial Co2Cr0.6Fe0.4Al/MgO/CoFe Tunnel Junctions
T. Marukame; T. Kasahara; K. Matsuda; T. Uemura; M. Yamamoto
IEEE Int’l Magnetics Conf., Digests, p.235, DD-07, Apr. 2005, [Peer-reviewed]
English, International conference proceedings

Magnetic and electrical properties of (La,Sr)MnO(3) sputtered on SrTiO(3)-buffered Si substrate
T Uemura; K Sekine; K Matsuda; M Yamamoto
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 44, 4B, 2604, 2607, Apr. 2005, [Peer-reviewed]
English, Scientific journal

Epitaxial growth and characterization of full-Huesler alloy Co2Cr0.6Fe0.4Al thin films for magnetic tunnel junctions
T. Marukame; T. kasahara; K. Matsuda; T. Uemura; M. Yamamoto
2nd Int. Workshop on Ubiquitous Knowledge Network Environment, Proceedings, vol.2, pp.383-389, DD-07, Mar. 2005
English

Fully epitaxial magnetic tunnel junctions using full-Heusler alloy thin film
M. Yamamoto; T. Uemura; K. Matsuda
2nd Int. Workshop on Ubiquitous Knowledge Network Environment, Proceedings, vol.2, pp.289-299, Mar. 2005, [Invited]
English

Fabrication of fully epitaxial magnetic tunnel junctions using full-Heusler alloy Co2Cr0.6Fe0.4Al thin film and MgO tunnel barrier
T Marukame; T Kasahara; K Matsuda; T Uemura; M Yamamoto
JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 44, 16-19, L521, L524, 2005, [Peer-reviewed]
English, Scientific journal

Four-valued magnetic random access memory based on magneto tunnel junction and resonant tunneling diode
T Uemura; M Yamamoto
JOURNAL OF MULTIPLE-VALUED LOGIC AND SOFT COMPUTING, 11, 5-6, 467, 479, 2005, [Peer-reviewed]
English, Scientific journal

Magnetic anisotropy study for GaMnAs-based magnetic tunnel junction
T Uemura; T Sone; K Matsuda; M Yamamoto
JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 44, 42-45, L1352, L1354, 2005, [Peer-reviewed]
English, Scientific journal

T. Uemura, K. Sekine, K. Matsuda and M. Yamamoto
T. Uemura; K. Sekine; K. Matsuda; M. Yamamoto
49th Annual Conf. on Magnetism and Magnetic Materials, Abstracts, vol49, p.54, Nov. 2004, [Peer-reviewed]
English, International conference proceedings

Epitaxial growth of Fe/MgO/Fe heterostructures on SrTiO3 substrates by magnetron sputtering
T. Marukame; K.-i. Matsuda; T. Uemura; M. Yamamoto
49th Annual Conf. on Magnetism and Magnetic Materials, Abstracts, vol49, p.329, Nov. 2004, [Peer-reviewed]
English, International conference proceedings

Magnetic and Electrical Properties of (La, Sr)MnO3 Sputtered on SrTiO3-buffered Si Substrate
T. Uemura; Y. Takagi; K. Sekine; K. Matsuda; M. Yamamoto
2004 Int’l Conf. on Solid State Devices and Materials, Extended Abstracts, pp.600-601, Sep. 2004, [Peer-reviewed]
English, International conference proceedings

Novel magnetic random access memory cell consisting of magnetic tunnel junction connected in parallel with negative differential resistance device
T Uemura; S Honma; T Marukame; M Yamamoto
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 43, 4B, 2114, 2117, Apr. 2004, [Peer-reviewed]
English, Scientific journal

Observation of clear negative differential resistance characteristics in GaAsNSe/GaAs and GaAsNSb/GaAs multiple quantum wells at room temperature
K Uesugi; M Kurimoto; Suemune, I; M Yamamoto; T Uemura; H Machida; N Shimoyama
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, 21, 2-4, 727, 731, Mar. 2004, [Peer-reviewed]
English, Scientific journal

Large enhancement of tunneling magnetoresistance ratio in magnetic tunnel junction connected in series with tunnel diode
T Uemura; S Honma; T Marukame; M Yamamoto
JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, 43, 1A-B, L44, L46, Jan. 2004, [Peer-reviewed]
English, Scientific journal

Proposal and Experimental Demonstration of Novel MRAM Cell Using Magnetic Tunnel Junction in Combination with Negative Differential Resistance Device
M. Yamamoto; T. Uemura
1st Int. Workshop on Ubiquitous Knowledge Network Environment, Proceedings, vol.1, pp.469-480, Nov. 2003, [Invited]
English

Proposal and experimental demonstration of magnetic tunnel junction connected in parallel with tunnel diode
T Uemura; S Honma; T Marukame; M Yamamoto
ELECTRONICS LETTERS, 39, 21, 1549, 1551, Oct. 2003, [Peer-reviewed]
English, Scientific journal

Demonstration of Enhanced Tunneling Magneto Resistance Ratio for a Magnetic Tunnel Junction Connected in Parallel with a Tunnel Diode
T. Uemura; S. Honma; T. Marukame; M. Yamamoto
2003 Int’l Conf. on Solid State Devices and Materials, Extended Abstracts, pp.618-619, Sep. 2003, [Peer-reviewed]
English, International conference proceedings

Proposal and analysis of a ferromagnetic triple-barrier resonant-tunneling spin filter
T Uemura; T Marukame; M Yamamoto
IEEE TRANSACTIONS ON MAGNETICS, 39, 5, 2809, 2811, Sep. 2003, [Peer-reviewed]
English, Scientific journal

Observation of Large Room-temperature Negative Differential Resistance in GaAsNSe/GaAs and GaAsNSb/GaAs Superlattices Grown on (001) GaAs
K. Uesugi; M. Kurimoto; I. Suemune; M. Yamamoto; T. Uemura; H. Machida; N. Shimoyama
The 11th Int’l. Conf. on Modulated Semiconductor Structures (MSS11), Workbook, vol.11, pp.266-267, Jul. 2003, [Peer-reviewed]
English, International conference proceedings

Proposal and analysis of a ferromagnetic triple-barrier resonant-tunneling spin filter
T. Uemura; T. Marukame; M. Yamamoto
Intermag 2003 - Program of the 2003 IEEE International Magnetics Conference, GD-03, Institute of Electrical and Electronics Engineers Inc., 2003, [Peer-reviewed]
English, International conference proceedings

Proposal of four-valued MRAM based on MTJ/RTD structure
T Uemura; M Yamamoto
33RD INTERNATIONAL SYMPOSIUM ON MULTIPLE-VALUED LOGIC, PROCEEDINGS, vol.33, 273, 278, 2003, [Peer-reviewed]
English, International conference proceedings

Fabrication of Self-Aligned Surface Tunnel Transistors with a 80-nm Gate Length.
Chun Yong Jin; Uemura Tetsuya; Baba Toshio
Japanese Journal of Applied Physics, 39, 12, L1273, L1276, The Japan Society of Applied Physics, 2000
English, A novel method using electron-beam (EB) lithography and regrowth for fabricating self-aligned InGaAs-based surface tunnel transistors (STTs) with sub-micron gate lengths has been developed. The shape of regrowth layer on the gate region is significantly affected not only by the gate lengths but also by the thickness of the regrowth layer. During regrowth, (111) facets are formed at the edges of the gate region while the (100) surface is maintained at the center. The shape changes to triangular consisting of (111) facets as gate length decreases below 150 nm due to the slow growth rate of the (111) facets compared to the (100) surface. The 80-nm STTs were fabricated by controlling the shape of the regrowth layer, and no deposition of the regrowth layer on the sidewall, which causes leakage current, occurred. The successful operation of InGaAs-based 80-nm STTs with clear negative differential resistance (NDR) characteristics and a gate-controlled peak current was obtained at room temperature.

Self-Aligned Surface Tunnel Transistors Fabricated by a Regrowth Technique.
Chun Yong Jin; Uemura Tetsuya; Baba Toshio
Japanese Journal of Applied Physics, 38, 10, L1163, L1165, The Japan Society of Applied Physics, 1999
English, A self-aligned process for fabricating surface tunnel transistors (STTs) has been developed in an attempt to improve both miniaturization and integration of STTs. In this process, the keys to obtaining a flat regrown layer and fine tunnel junctions are to keep from contaminating the surface during the lithography process before regrowth and to control the side-wall profile of the gate region in which tunnel junctions are formed. The carbon contamination can be reduced significantly by using a double hard mask consisting of Si₃N₄ and SiO₂, and oxygen contamination can be removed by atomic hydrogen irradiation. The side-wall profile, that is etched surface morphology and side-wall angle, can be optimized by adjusting the composition of the H₃PO₄:H₂O₂:H₂O etching solution. During regrowth, a flat surface morphology and fine tunnel junctions were obtained at the low temperature of 400°C. Self-aligned InGaAs-based STTs with gate-controlled negative differential resistance (NDR) characteristics showing a peak-to-valley (P/V) ratio of 2.5 were obtained.

Surface Tunnel Transistor: Gate-Controlled Lateral Interband Tunneling Device.
Uemura Tetsuya; Baba Toshio
Japanese Journal of Applied Physics, 35, 3, 1668, 1675, The Japan Society of Applied Physics, 1996
English, We demonstrated a novel three-terminal tunnel device, the Surface Tunnel Transistor (STT), in which lateral interband tunneling current between source and drain is controlled by a gate voltage. The STT consists of a highly degenerate drain whose polarity is opposite that of the source, a channel with an insulated gate, and a source connected to the channel. The basic characteristics of the STTs were investigated by fabricating three types of STTs with mesa structures using a GaAs/AlGaAs system, as well as by a two-dimensional device simulation. An enhancement-type STT (E-STT) in which no electrons are accumulated on the channel surface at thermal equilibrium exhibited unsaturated transistor characteristics due to interband tunneling under source-drain reverse bias conditions. To increase the current density, a modulation doped STT (MD-STT) in which the channel was formed by modulation doping was also fabricated, and a tunneling current about 10⁴ times larger than that of the E-STT was obtained. Moreover, the MD-STT showed negative differential resistance (NDR) characteristics under source-drain forward bias conditions. A channel doped STT (CD-STT) in which the channel region was directly doped with donors showed improved NDR characteristics with a peak current density of 3.7 µ A/µ m and a peak-to-valley current ratio (PVR) of 1.5 at room temperature. These values are larger than those of the MD-STT by a factor of 10³ and 1.5, respectively. Furthermore, a PVR as high as 4.8 was obtained for the CD-STT by inserting a blocking layer between the drain and the overlapped channel layer to reduce the valley current.

Improved Negative Differential Resistance Characteristics in Surface Tunnel Transistors
Uemura Tetsuya; Baba Toshio
Jpn J Appl Phys, 33, 10, L1363, L1366, The Japan Society of Applied Physics, 01 Oct. 1994
English, We propose and demonstrate a new type of Surface Tunnel Transistor (STT) which displays improved negative differential resistance (NDR) characteristics. In this device, called channel-doped STT (CD-STT), the channel region is direclly doped with donors in order to increase the channel carrier density. A peak current is obtained that is 103 times larger than that of a conventional STT. To reduce the valley current further, a blocking layer consisting of an i-GaAs is inserted at the gate/drain overlap region. The resulting device, called blocking layer inserted STT (BLI-STT), exhibits excellent NDR characteristics with a peak-to-valley ratio (PVR) of 4.8 at room temperature, a value which is more than 4 times larger than that of a conventional STT.

First Observation of Negative Differential Resistance in Surface Tunnel Transistors
Uemura Tetsuya; Baba Toshio
Jpn J Appl Phys, 33, 2, L207, L210, The Japan Society of Applied Physics, 15 Feb. 1994
English, Negative differential resistance (NDR) due to an interband tunneling has been observed at room temperature for the first time in a Surface Tunnel Transistor (STT) under forward-bias conditions. To produce clear NDR characteristics, the electron density in the channel was designed to be high enough to induce band overlap at the channel/drain junction. In order to increase the tunneling current further, a channel doped structure, in which a thin n+-GaAs layer was inserted between a p+-GaAs layer (drain) and an i-GaAs layer, was proposed. This channel doped STT exhibited a peak current density of 8 µ A/µ m, which is 280 times larger than that of the conventional STT.

Characterization of Depletion-Type Surface Tunnel Transistors
Uemura Tetsuya; Baba Toshio
Jpn J Appl Phys, 31, 12, L1727, L1729, The Japan Society of Applied Physics, 20 Dec. 1992
English, A depletion-type Surface Tunnel Transistor (D-STT) is proposed to increase the tunneling current compared to that of the enhancement-type STT (E-STT) previously reported. The most important feature of the D-STT is the use of a modulation doped structure in order to accumulate a high concentration of electrons under the gate. GaAs/AlGaAs D-STTs, which are fabricated by using an MBE regrowth technique, exhibit depletion-mode transistor action with a larger operation current than that displayed by the E-STT. This increase in current is due to a higher two-dimensional electron gas concentration at the i-GaAs surface. Moreover, the high gate leakage current which limits GaAs E-STT operation is reduced in the case of the D-STT by a factor of $10^{6}$.

■ Other Activities and Achievements

Pd/Co2MnGa及びPd/Co2MnSi垂直磁化膜における電流誘起トルクの評価
小山貴也; 渡辺健太; 植村哲也; 山ノ内路彦, 第49回日本磁気学会学術講演会, Sep. 2025
Japanese, Summary national conference

Non local detection of current induced magnetization switching using lateral spin-valve device
Mineto Ogawa; Yu Osada; Michihiko Yamanouchi; Tetsuya Uemura, 第86回応用物理学会秋季学術講演会, Sep. 2025, [Corresponding author]
English, Summary national conference

Observation of anisotropic spin dynamics in a (001) GaAs/AlGaAs heterointerface suitable for electrical spin wave injection
Kento Sugawara; Koga Akagi; Jun Ishihara; Daiki Sekine; Sota Yamamoto; Mineto Ogawa; Tetsuya Uemura; Makoto Kohda, 第86回応用物理学会秋季学術講演会, Sep. 2025
English, Summary national conference

Two-stage Formation of an Anomalously Large Nuclear Field in Bulk n-AlGaAs
Andong Shen; Reina Kaji; Sota Yamamoto; Tetsuya Uemura; Satoru Adachi, 第86回応用物理学会秋季学術講演会, Sep. 2025
English, Summary national conference

先端半導体バイナリニューラルネットワーク応用に向けたCo2MnSi/MgO/Co2MnSi強磁性トンネル接合の評価
丸亀孝生; 楠瀬黎; 植村哲也, 第72回応用物理学会春季学術講演会, Mar. 2025
Japanese, Summary national conference

Thickness Dependence of current-induced effective magnetic field acting on domain wall in SrRuO3
Kanata Nakamura; Tomoki Shibata; Takaya Koyama; Michihiko Yamanouchi; Tetsuya Uemura, 第72回応用物理学会春季学術講演会, Mar. 2025
Japanese, Summary national conference

Pd/Co2MnGa垂直磁化膜における磁壁に作用する電流誘起有効磁場の面内磁場による変調
小山貴也; 西岡優輝; 植村哲也; 山ノ内路彦, 第72回応用物理学会春季学術講演会, Mar. 2025
Japanese, Summary national conference

Effective magnetic field by orbital torque in Pd/Co2MnGa perpendicular magnetization films
Takaya Koyama; Kenta Watanabe; Tetsuya Uemura; Michihiko Yamanouchi, 第72回応用物理学会春季学術講演会, Mar. 2025
English, Summary national conference

Current-induced domain wall motion in perpendicularly magnetizsed Pd/Co2MnGa thin films
T. Koyama, Y. Nishioka, T. Uemura and M. Yamanouchi, Physics and Application of Spatial structures on Spin, QuAntum state and Light (PASSQAL-1), Oct. 2024
English, Summary international conference

Spin injection intos GaAs using perpendicularly magnetizsed Mn/Co bilyar
M. Ogawa; K. Nara; M. Yamanouchi; T. Uemura, Physics and Application of Spatial structures on Spin, QuAntum state and Light (PASSQAL-1), Oct. 2024, [Corresponding author]
English, Summary international conference

Mn/Co垂直磁化膜/n-GaAsヘテロ接合を用いた横型スピンバルブ素子の評価
小川峰登; 奈良晃太郎; 山ノ内路彦; 植村哲也, 第48回日本磁気学会学術講演会, Sep. 2024, [Corresponding author]
Japanese, Summary national conference

Electrical spin injection into GaAs from perpendicularly magnetized Mn/Co bilayers
Kotaro Nara; Mineto Ogawa; Michihiko Yamanouchi; Tetsuya Uemura, 第85回応用物理学会秋季学術講演会, Sep. 2024, [Corresponding author]
Japanese, Summary national conference

希薄窒化GaNAsを⽤いた近⾚外スピン受光ダイオードの磁場特性
矢野龍弥; 峯山大輝; 江藤亘平; 中間海音; 橋本英考; 峰久恵輔; 小川峰登; 高山純一; 石川史太郎; 植村哲也; 樋浦諭志; 村山明宏, 第85回応用物理学会秋季学術講演会, Sep. 2024
Japanese, Summary national conference

GaAs 上に成長したMnGa/Fe 垂直磁化膜のスピン軌道トルク磁化反転と有効磁場の観測
小川峰登; 原拓也; 長谷部俊; 山ノ内路彦; 植村哲也, 第27回半導体におけるスピン工学の基礎と応用, Mar. 2024, [Corresponding author]
Japanese, Summary national conference

MnGa の成長とスピン軌道トルク磁化反転に対する極薄Fe 中間層の影響
小川峰登; 原拓也; 長谷部俊; 山ノ内路彦; 植村哲也, 第47回日本磁気学会学術講演会, Sep. 2023
Japanese, Summary national conference

Co2Mn(Al,Ga) 薄膜における異常ホール効果とネルンスト効果の評価
菅原聖威; 山ノ内路彦; 植村哲也, 第47回日本磁気学会学術講演会, Sep. 2023, [Corresponding author]
Japanese, Summary national conference

Interaction between spin-orbit torque and domain walls in a Pt/SrRuO₃ structure
酒井貴樹; 野土翔登; 長浜太郎; 植村哲也; 山ノ内路彦, 応用物理学会北海道支部/日本光学会北海道支部合同学術講演会講演予稿集, 56th-17th (CD-ROM), 2021

Highly-efficient electrical spin injection into semiconductors using a half-metal spin source
植村哲也, 応用物理, 83, 3, 194, 199, Mar. 2014
応用物理学会, Japanese

Temperature dependence of spin-dependent tunneling resistance of Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
Y. Honda; H.-x. Liu; T. Uemura; M. Yamamoto, 49th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.49, p.5, A-5, Dec. 2013
Japanese, Summary national conference

Demonstration of high spin injection efficiency in Co2MnSi/CoFe/n-GaAs junctions
Y. Ebina; T. Akiho; H.-x. Liu; M. Yamamoto; T. Uemura, 49th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.49, p.4, A-4,, Dec. 2013
Japanese, Summary national conference

Spin lifetime in strained InGaAs channels investigated through all electrical spin injection and detection
T. Akiho; M. Yamamoto; T. Uemura, The 18th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-18), Program and Abstracts, vol.18, p.13, A5, Dec. 2013
English, Summary national conference

Dynamic nuclear polarization observed in Co2MnSi/CoFe/n-GaAs heterojunctions
T. Akiho; H.-x. Liu; M. Yamamoto; T. Uemura, Digests of the 37th Annual Conference on Magnetics in Japan 2013, vol.37, p.366, 6aC-8, Sep. 2013
Japanese, Summary national conference

Effect of CoFe insertion on spin injection properties in Co2MnSi/CoFe/n-GaAs junctions
Y. Ebina; T. Akiho; H.-x. Liu; M. Yamamoto; T. Uemura, Digests of the 37th Annual Conference on Magnetics in Japan 2013, vol.37, p.365, 6aC-7, Sep. 2013
Japanese, Summary national conference

Giant tunneling magnetoresistance in fully epitaxial Co2(Mn, Fe)Si/MgO/ Co2(Mn, Fe)Si magnetic tunnel junctions
T. Kawami; H.-x. Liu; Y. Honda; T. Uemura; F.-y. Shi; P. M. Voyles; M. Yamamoto, Digests of the 37th Annual Conference on Magnetics in Japan 2013, vol.37, p.53, 3pC-8, Sep. 2013
Japanese, Summary national conference

Effect of nonstoichiometry on the half-metallicity of Co2MnSi thin films with various Mn compositions
Y. Honda; G.-f. Li; H.-x. Liu; M. Arita; K.-i. Matsuda; T. Uemura; M. Yamamoto; T. Saito; Y. Miura; M. Shirai, Digests of the 37th Annual Conference on Magnetics in Japan 2013, vol.37, p.52, 3pC-7, Sep. 2013
Japanese, Summary national conference

Highly-efficient dynamic nuclear polarization in GaAs using a Heusler-alloy spin source
T. Akiho; H.-x. Liu; K.-i. Matsuda; M. Yamamoto; T. Uemura, Extended Abstracts of the 74th Autumn Meeting 2013, The Japan Society of Applied Physics (DVD-ROM), vol.74, 10-041,20a-C15-3, Sep. 2013
English, Summary national conference

Giant tunneling magnetoresistance in fully epitaxial Co2(Mn, Fe)Si/MgO/ Co2(Mn, Fe)Si magnetic tunnel junctions
T. Kawami; H.-x. Liu; Y. Honda; T. Uemura; F.-y. Shi; P. M. Voyles; M. Yamamoto, Extended Abstracts of the 74th Autumn Meeting 2013, The Japan Society of Applied Physics (DVD-ROM), vol.74, 10-018,18a-C15-4, Sep. 2013
English, Summary national conference

Half-metallic Heusler alloy thin films for spintronic devices
M. Yamamoto; T. Uemura, Extended Abstracts of the 74th Autumn Meeting 2013, The Japan Society of Applied Physics (DVD-ROM), vol.74, 077,18p-C15-2, Sep. 2013, [Invited]
Japanese, Summary national conference

Annealing temperature dependence of spin signals observed inCo2MnSi/CoFe/n-GaAs through four-terminal non-local geometry
T. Akiho; J. Shan; K.-i. Matsuda; M. Yamamoto; T. Uemura, Extended Abstracts of the 60th JSPS Spring Meeting, 2013 (DVD-ROM), vol.60, 10-049, 28a-A7-5,, Mar. 2013
English, Summary national conference

Influence of interfacetermination layeron temperature dependenceof tunneling magnetoresistance of Co2MnSi/MgO-based magnetic tunnel junctions
H.-x. Liu; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto; F.-y. Shi; P. Voyles, Extended Abstracts of the 60th JSPS Spring Meeting, 2013 (DVD-ROM), vol.60, 10-038, 30p-A7-7, Mar. 2013
English, Summary national conference

Co₂MnSi/CoFe/MgO/SiにおけるHanle信号のMgO膜厚依存性
藤澤潤; 松田健一; 山本眞史; 植村哲也, 第48回応用物理学会北海道支部学術講演会講演予稿集, 59, 11 Jan. 2013
Japanese, Summary national conference

MgO thickness dependence of Hanle signal in Co2MnSi/CoFe/MgO/Si
J. Fujisawa; K.-i. Matsuda; M. Yamamoto; T. Uemura, 48th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.48, p.59, B-27, Jan. 2013
Japanese, Summary national conference

Superconducting proximity effect in Nb/Cu50Ni50 bilayers and ther transport properties
Y. Ebina; K.-i. Matsuda; T. Uemura; M. Yamamoto, 48th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.48, p.58, B-26, Jan. 2013
Japanese, Summary national conference

Spin injectioin from ferromagnet into InGaAs thfough GaAs tunnel barrier
T. Torino; K.-i. Matsuda; M. Yamamoto; T. Uemura, 48th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.48, p.17, A-17, Jan. 2013
Japanese, Summary national conference

Tunnel barrier thickness dependence of Hanle signals in CoFe/MgO/SC (SC= Si or Ge) investigated through three-terminal configuration
T. Uemura; G.-f. Li; J. Fujisawa; K.-i. Matsuda; M. Yamamoto, The 17th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-17), Program and Abstracts, vol.17, p.25,P5, Dec. 2012
Japanese, Summary national conference

Spin injection into GaAs from highly spin-polarized ferromagnetic electrode
T. Uemura; T. Akiho; K.-i. Matsuda; M. Yamamoto, The 17th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-17), Program and Abstracts, vol.17, p.19, B5, Dec. 2012, [Invited]
Japanese, Summary national conference

Co50Fe50電極からGaAs へのスピン注入の電気的検出
T. Uemura; T. Akiho; M. Harada; K.-i. Matsuda; M. Yamamoto, Digests of the 35th Annual Conference on Magnetics in Japan 2011, vol.35, p.338, 30aB-3, Sep. 2012
Japanese, Summary national conference

Transient oblique Hanle signals observed in a Co2MnSi/CoFe/n-GaAs Schottky tunnel junction with non-local four-terminal configuration
Jinhai Shan; Takafumi Akiho; Ken-ichi Matsuda; Masafumi Yamamoto; Tetsuya Uemura, Extended Abstracts of the 73th Autumn Meeting 2012, The Japan Society of Applied Physics (DVD-ROM), vol.73, 10-100, 14a-H6-10, Sep. 2012
Japanese, Summary national conference

MgO tunnel barrier thickness dependence of three-terminal Hanle-type signals in CoFe/MgO/n-Ge tunnel junctions
G.-f. Li; M. Miki; K.-i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts of the 73th Autumn Meeting 2012, The Japan Society of Applied Physics (DVD-ROM), vol.73, 10-052, 13p-H6-6, Sep. 2012
English, Summary national conference

Spin-polarization measurement for Heusler alloy Co2MnSi using Co2MnSi/MgO/NbN junctions
K. ?i. Matsuda; T. Shinoki; T. Uemura; M. Yamamoto, Extended Abstracts of the 73th Autumn Meeting 2012, The Japan Society of Applied Physics (DVD-ROM), vol.73, 10-020, 12a-H6-2, Sep. 2012
Japanese, Summary national conference

Temperature dependence of spin-dependent tunneling resistances of fully epitaxial Co2MnSi-based magnetic tunnel junctions
H.-x. Liu; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts of the 73th Autumn Meeting 2012, The Japan Society of Applied Physics (DVD-ROM), vol.73, 10-009, 11p-H6-9, Sep. 2012
English, Summary national conference

MgO thickness dependence of spin accumulation signal in CoFe/MgO/Si
Tetsuya Uemura; Jun Fijisawa; Ken-ichi Matsuda; Masafumi Yamamoto, Extended Abstracts of the 59th Spring Meeting2012, The Japan Society of Applied Physics (DVD-ROM), vol.59, 10-056, 17a-B4-9, Mar. 2012
Japanese, Summary national conference

Electrical spin injection from Co2MnSi Heusler alloy into GaAsand electrical detection of dynamic nuclear polarization
Takafumi Akiho; Tetsuya Uemura; Ken-ichi Matsuda; Masafumi Yamamoto, Extended Abstracts of the 59th Spring Meeting2012, The Japan Society of Applied Physics (DVD-ROM), vol.59, 10-059, 17a-B4-12, Mar. 2012
Japanese, Summary national conference

Fabrication of fully epitaxial magnetic tunnel junctions with a Heusler alloy Co2MnSi thin film and a MgO barrier on Ge(001) substrates
G.-f. Li; T. Taira; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts of the 59th Spring Meeting2012, The Japan Society of Applied Physics (DVD-ROM), vol.59, 10-005, 16a-B4-5, Mar. 2012
English, Summary national conference

Spin-dependent transport characteristics of epitaxial magnetic tunnel junctions of CoFe/MgO/CoFe ultrathin layer/Co2MnSi
H.-x. Liu; Y. Honda; T. Taira; K.-i. Matsuda; T. Uemura; Y. Miura; M. Shirai; M. Yamamoto, Extended Abstracts of the 59th Spring Meeting2012, The Japan Society of Applied Physics (DVD-ROM), vol.59, 10-006, 16a-B4-6, Mar. 2012
English, Summary national conference

Detection of nuclear magnetic filed and spin transport in Co2MnSi/CoFe/n-GaAs structures
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto, 47th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.47, p.78, C-9, Jan. 2012
Japanese, Summary national conference

Tunnel magnetoresistance in fully epitaxial CoFe/MgO/CoFe magnetic tunnel junctions on Ge(001) substrates via a MgO interlayer
G.-f. Li; T. Taira; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto, 47th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.47, p.77, C-8, Jan. 2012
English, Summary national conference

Spin-polarization measurement for Heusler alloy Co2MnSi using Co2MnSi/MgO/NbN heterostructures
T. Shinoki; K.-i. Matsuda; T. Taira; T. Uemura; M.Yamamoto, 47th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.47, p.73, C-4, Jan. 2012
Japanese, Summary national conference

Spin-polarized transport in fully epitaxial CoFe/MgO/CoFe ultrathin layer/Co2MnSi magnetic tunnel junction
H.-x. Liu; Y. Honda; T. Taira; K.-i. Matsuda; T. Uemura; Y. Miura; M. Shirai; M.Yamamoto, 47th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.47, p.72, C-3, Jan. 2012
English, Summary national conference

Spin transport properties of fully epitaxial magnetic tunnel junctions of CoFe/MgO/CoFe ultrathin layer/Co2MnSi
H.-x. Liu; T. Taira; Y. Honda; K. -i. Matsuda; T. Uemura; M. Yamamoto; Y. Miura; M. Shirai, 5th Int’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Proceedings of GCOE-NGIT 2012, vol.5, p.289, N-06, Jan. 2012
English, Summary international conference

Tunnel magnetoresistance in fully epitaxial CoFe/MgO/CoFe magnetic tunnel junctions on Ge(001) substrates via a MgO interlayer
G.-f. Li; T. Taira; H.-x. Liu; K. ?i. Matsuda; T. Uemura; M. Yamamoto, 5th Int’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Proceedings of GCOE-NGIT 2012, vol.5, p.287, N-05, Jan. 2012
English, Summary international conference

Spin injection from Co2MnSi into GaAs and detection of dynamic nuclear polarization
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto, The 16th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-16), Program and Abstracts, vol.16, pp.121-122, F4, Nov. 2011
Japanese, Summary national conference

Epitaxial growth of Heusler alloy Co2MnSi thin films on Ge(001) substrates via a MgO interlayer
G.-f. Li; T. Taira; K.-i. Matsuda; M. Arita; T. Uemura; M. Yamamoto, Digests of the 35th Annual Conference on Magnetics in Japan 2011, vol.35, p.4, 27aB-4, Sep. 2011
English, Summary national conference

Oscillations in tunneling resistances commonly observed for the parallel and antiparallel magnetization orientations as a function of barrier thickness in epitaxial Co2MnSi/MgO/Co2MnSi MTJs
Y. Honda; S. Hirata; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts of the 72th Autumn Meeting2011, The Japan Society of Applied Physics (DVD-ROM), vol.72, 10-058, 2a-S-5, Aug. 2011
Japanese, Summary national conference

Spin injection from Co50Fe50 into GaAs at room temperature
Tetsuya Uemura; Takafumi Akiho; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto, Extended Abstracts of the 72th Autumn Meeting2011, The Japan Society of Applied Physics (DVD-ROM), vol.72, 10-028, 31a-ZS-5, Aug. 2011
Japanese, Summary national conference

Influence of MgO insertion on spin dependent transport properties ofCoFe/n-GaAs hetero junctions
Takafumi Akiho; Tetsuya Uemura; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto, Extended Abstracts of the 72th Autumn Meeting2011, The Japan Society of Applied Physics (DVD-ROM), vol.72, 10-027, 31a-ZS-4, Aug. 2011
Japanese, Summary national conference

Structural and magnetic properties of epitaxially grown Heusler alloyCo2MnSi/MgO heterostructures on Ge(001) substrates
G.-f. Li; T. Taira; K.-i. Matsuda; M. Arita; T. Uemura; M. Yamamoto, Extended Abstracts of the 72th Autumn Meeting2011, The Japan Society of Applied Physics (DVD-ROM), vol.72, 10-003, 30a-ZS-3, Aug. 2011
English, Summary national conference

Pronounced oscillations in spin-dependent tunneling resistances of epitaxial MTJswith Co2MnSi electrodes and a MgO barrier
Y. Honda; S. Hirata; G.-f. Li; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts of the 58th Spring Meeting2011, The Japan Society of Applied Physics (DVD-ROM), vol.58, 10-090, 26p-KR-7, Mar. 2011
Japanese, Summary national conference

Epitaxial growth of Co2MnSi/MgO heterostructures on Ge(001) substrates
G.-f. Li; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts of the 58th Spring Meeting2011, The Japan Society of Applied Physics (DVD-ROM), vol.58, 10-007, 25a-KM-7, Mar. 2011
English, Summary national conference

Electrical detection of spin injection in Co50Fe50/n-GaAs
T. Uemura; M. Harada; T. Akiho; K.-i. Matsuda; M. Yamamoto, Extended Abstracts of the 58th Spring Meeting2011, The Japan Society of Applied Physics (DVD-ROM), vol.58, 10-042, 24a-KQ-11, Mar. 2011
Japanese, Summary national conference

Effects of the insertion of a MgO tunnel barrier on tunneling characteristics in ferromagnet/n-GaAs hetero junction
M. Harada; T. Akiho; K.-i. Matsuda; T. Uemura; M. Yamamoto, 46th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.46, p.44, B-11, Jan. 2011
Japanese, Summary national conference

Spin-dependent tunneling resistance as a function of MgO barrier thickness in magnetic tunnel junctions withCo2MnSi thin films
S. Hirata; Gui-fang Li; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto, 46th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.46, p.43, B-10, Jan. 2011
Japanese, Summary national conference

Epitaxial growth of Heusler alloy Co2MnSi thin films on MgO-buffered Ge substrate
G. -f. Li; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto, 4th Int’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Proceedings of GCOE-NGIT 2011, vol.4, p.281, N-04, Jan. 2011
English, Summary international conference

High tunnel magnetoresistance in fully epitaxial CoFe-buffered Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
H.-x. Liu; T. Taira; K. -i. Matsuda; T. Uemura; M. Yamamoto, 4th Int’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Proceedings of GCOE-NGIT 2011, vol.4, p.283, N-05, Jan. 2011
English, Summary international conference

Effects of MgO tunnel barriers on tunneling anisotropic magnetoresistance in Co2MnSi/n-GaAs junctions
T. Akiho; M. Harada; T. Uemura; K. ?i. Matsuda; M. Yamamoto, The 15th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-15),Program and Abstracts, vol.15, pp.97-98, D1, Dec. 2010
Japanese, Summary national conference

Spin-dependent transport properties in Co2MnSi/MgO/n-GaAs junctions
T. Uemura; M. Harada; T. Akiho; K. ?i. Matsuda; M. Yamamoto, Digest of the 34th Annual Conference on MAGNETICS in Japan 2010, vol.34, p.233, 6pB-12, Sep. 2010
Japanese, Summary national conference

High tunnel magnetoresistance in fully epitaxial Co50Fe50-buffered Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
H.?x. Liu; T. Taira; Y. Honda; K. -i. Matsuda; T. Uemura; M. Yamamoto, Digest of the 34th Annual Conference on MAGNETICS in Japan 2010, vol.34, p.220, 6aB-9, Sep. 2010
English, Summary national conference

Differential Conductance Characteristics and their temperature dependences of NbN/Co2Cr0.6Fe0.4Al/NbN junctions
K. ?i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts of the 71th Autumn Meeting, The Japan Society of Applied Physics (DVD-ROM), vol.71, 11-017, 14a-P3-17, Sep. 2010
Japanese, Summary national conference

Giant oscillations in spin-dependent tunneling resistances as a function of barrier thickness in fully epitaxial magnetic tunnel junctions with a MgO barrier
M. Yamamoto; T. Marukame; T. Ishikawa; T. Taira; K.-i. Matsuda; T. Uemura, Extended Abstracts of the 71th Autumn Meeting, The Japan Society of Applied Physics (DVD-ROM), vol.71, 10-064, 14p-J-4, Sep. 2010
Japanese, Summary national conference

Spin-dependent transport properties of Co2MnSi/MgO/n-GaAs tunnel junctions
M. Harada; T. Akiho; T. Uemura; K. ?i. Matsuda; M. Yamamoto, Extended Abstracts of the 71th Autumn Meeting, The Japan Society of Applied Physics (DVD-ROM), vol.71, 10-056, 17p-A-1, Sep. 2010
Japanese, Summary national conference

High tunnel magnetoresistance of up to 450% at room temperature in epitaxial magnetic tunnel junctions with a Heusler-alloy spin source and a MgO barrier
H.-x. Liu; T. Taira; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts of the 71th Autumn Meeting, The Japan Society of Applied Physics (DVD-ROM), vol.71, 10-002, 14a-F-2, Sep. 2010
English, Summary national conference

Tunnel magnetoresistance characteristics of fully epitaxial Co2MnAl/MgO/CoFe MTJs with various Mn compositions in Co2MnAl electrodes
G.-f. Li; T. Taira; S. Hirata; K.-I. Matsuda; T. Uemura; M. Yamamoto, Collected Abstracts of the 2010 Autumn (147th) Meeting of The Japan Institute of Metals,No. 483, vol.147, p.328, Sep. 2010
English, Summary national conference

Spin-dependent conductance characteristics of Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions
S. Hirata; T. Taira; T. Ishikawa; K; ?i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts (The 57th Spring Meeting, 2010), The Japan Society of Applied Physics (DVD-ROM), vol.57, 10-008, 17a-ZH-8, Mar. 2010
Japanese, Summary national conference

Defects induced in nonstoichiometric Co2MnGe thin films investigated through saturation magnetization
G.-f. Li; T. Taira; S. Hirata; Y. Honda; K. ?i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts (The 57th Spring Meeting, 2010), The Japan Society of Applied Physics (DVD-ROM), vol.57, 10-007, 17a-ZH-7, Mar. 2010
English, Summary national conference

Interfacial-structure dependence of TAMR effect and magnetic crystalline anisotropy in a Co2MnSi/n-GaAs junctions
M. Harada; T. Akiho; K. ?i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts (The 57th Spring Meeting, 2010), The Japan Society of Applied Physics (DVD-ROM), vol.57, 10-114, 19p-ZJ-19, Mar. 2010
Japanese, Summary national conference

Fabrication of Heusler-alloy-based magnetic tunnel junctions having an upper Co2MnSi electrode with various Mn compositions and having a Co50Fe50 lower electrode
H.-x. Liu; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto, Extended Abstracts (The 57th Spring Meeting, 2010), The Japan Society of Applied Physics (DVD-ROM), vol.57, 10-108, 19p-ZJ-13, Mar. 2010
English, Summary national conference

Influence of film composition on the saturation magnetization of Co2MnGe thin films
G.-f. Li; T. Taira; S. Hirata; Y. Honda; K.?i. Matsuda; T. Uemura; M. Yamamoto, Collected Abstracts of the 2010 Spring (146th) Meetingof The Japan Institute of Metals, vol.146, p.158, S6.22, Mar. 2010
English, Summary national conference

Conductance characteristics of magnetic tunnel junctions with Heusler alloy Co2MnGe thin films fabricated with various film compositions
S. Hirata; T. Taira; K. ?i. Matsuda; T. Uemura; M. Yamamoto, Collected Abstracts of the 2010 Spring (146th) Meetingof The Japan Institute of Metals, vol.146, p.157, S6.20, Mar. 2010
Japanese, Summary national conference

Creation and control of spin current using Heusler alloys
T. Uemura; T. Ishikawa; M. Harada; T. Taira; K. ?i. Matsuda; M. Yamamoto, Collected Abstracts of the 2010 Spring (146th) Meetingof The Japan Institute of Metals, vol.146, p.156, S6.17, Mar. 2010, [Invited]
Japanese, Summary national conference

Effect of nonstoichiometry on saturation magnetization of Heusler alloy Co2MnGe thin films
G.-f. Li; T. Taira; S. Hirata; Y. Honda; K. ?i. Matsuda; T. Uemura; M. Yamamoto, 45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.45, p.88, C-31, Jan. 2010
English, Summary national conference

Fabrication and Transport Properties of NbN/Co2Cr0.6Fe0.4Al/NbN Junctions
S. Imai; T. Ishikawa; K. ?i. Matsuda; T. Uemura; M. Yamamoto, 45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.45, p.87, C-30, Jan. 2010
Japanese, Summary national conference

Tunneling anisotropic magnetoresistance effect in a Co2MnSi/n-GaAs Schottky junction
M. Harada; T. Akiho; K. ?i. Matsuda; T. Uemura; M. Yamamoto, 45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.45, p.86, C-29, Jan. 2010
Japanese, Summary national conference

Spin-dependent conductance characteristics of Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions fabricated with various film composition
S. Hirata; T. Taira; T. Ishikawa; K.?i. Matsuda; T. Uemura; M. Yamamoto, 45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.45, p.85, C-28, Jan. 2010
Japanese, Summary national conference

Fabrication of fully epitaxial NbN/MgO/Co-based Heusler alloy trilayers and their tunnel characteristics
N. Itabashi; T. Taira; K. ?i. Matsuda; T. Uemura; M. Yamamoto, 45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Collected Abstracts, vol.45, p.84, C-27, Jan. 2010
Japanese, Summary national conference

Tunnel magnetoresistance characteristics of Heusler-alloy-based magnetic tunnel junctions having an upper Co2MnSi electrode with various Mn compositions and having a Co50Fe50 lower electrode
H.-x. Liu; T. Ishikawa; K. -i. Matsuda; T. Uemura; M. Yamamoto, The 3rdInt’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Proceedings of GCOE-NGIT 2010, vol.3, p.225, N-03, Jan. 2010
English, Summary international conference

Effect of nonstoichiometry on saturation magnetization of Heusler alloy Co2MnGe thin film
G.-f. Li; T. Taira; S. Hirata; Y. Honda; K. ?i. Matsuda; T. Uemura; M. Yamamoto, The 3rdInt’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Proceedings of GCOE-NGIT, vol.3, p.228, N-05, Jan. 2010
English, Summary international conference

Tunneling spectroscopy of Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions
T. Taira; S. Hirata; G.-f. Li; K.-i. Matsuda; T. Uemura; M. Yamamoto, The 3rdInt’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Proceedings of GCOE-NGIT, vol.3, p.230, N-06, Jan. 2010
English, Summary international conference

Co₂MnSi/MgO/Co₂MnSi強磁性トンネル接合のトンネル磁気抵抗特性に対する薄膜組成比の影響
石川貴之; LIU H.‐X; 平智幸; 松田健一; 植村哲也; 山本眞史, 第33回日本磁気学会学術講演会講演概要集, 22, 12 Sep. 2009
Japanese, Summary national conference

Co₂MnGe/MgO/Co₂MnGe強磁性トンネル接合の製作とトンネル磁気抵抗特性
平智幸; 平田進之佑; 石川貴之; 松田健一; 植村哲也; 山本眞史, 2009年秋季第70回応用物理学会学術講演会講演予稿集 (CD-ROM), 2, 676, 08 Sep. 2009
Japanese, Summary national conference

エピタキシャルCo₂MnSi/n‐GaAs接合における異方性磁気抵抗
原田雅亘; 植村哲也; 松田健一; 山本眞史, 2009年秋季第70回応用物理学会学術講演会講演予稿集 (CD-ROM), 2, 704, 08 Sep. 2009
Japanese, Summary national conference

NbN/Co₂Cr_0.6Fe_0.4Al/NbN横型ジョセフソン接合の電気伝導特性
松田健一; 今井悟嗣; 石川貴之; 植村哲也; 山本眞史, 2009年秋季第70回応用物理学会学術講演会講演予稿集 (CD-ROM), 2, 677, 08 Sep. 2009
Japanese, Summary national conference

Report on "The 2008 Workshop for Refreshing Science in Sapporo (Hokkaido Univ.)"
ARITA Masashi; SUGAWARA Yo; UEMURA Tetsuya; ADACHI Satoshi; SUGAWARA Hirotake; KASAI Seiya; MATSUDA Ken-ichi; SATO Taketomo; TAKAHASHI Yasuo; FUKUI Takashi, 応用物理教育, 33, 1, 25, 30, 31 Jul. 2009
Japanese

エピタキシャルCoFe/n‐GaAs接合における磁気抵抗特性
今井洋介; 原田雅亘; 植村哲也; 松田健一; 山本眞史, 2009年春季第56回応用物理学関係連合講演会講演予稿集, 2, 791, 30 Mar. 2009
Japanese, Summary national conference

強磁性細線中を伝播する磁壁の構造および運動のTMR検出のシミュレーション
澤田圭佑; 植村哲也; 増田昌洋; 松田健一; 山本眞史, 2009年春季第56回応用物理学関係連合講演会講演予稿集, 2, 779, 30 Mar. 2009
Japanese, Summary national conference

Co₂Cr_0.6Fe_0.4Al/MgO/Co₂Cr_0.6Fe_0.4Al強磁性トンネル接合のスピン依存コンダクタンス特性
板橋直樹; 石川貴之; 米村和希; 松田健一; 植村哲也; 山本眞史, 第44回応用物理学会北海道支部学術講演会講演予稿集, 40, 08 Jan. 2009
Japanese, Summary national conference

ハーフメタル系強磁性体(Co₂Cr_0.6Fe_0.4Al)/超伝導体(NbN)二層薄膜のエピタキシャル成長
今井悟嗣; 石川貴之; 松田健一; 植村哲也; 山本眞史, 第44回応用物理学会北海道支部学術講演会講演予稿集, 47, 08 Jan. 2009
Japanese, Summary national conference

CoFe/n‐GaAs/CoFe横型接合における磁気抵抗特性
今井洋介; 原田雅亘; 植村哲也; 松田健一; 山本眞史, 第44回応用物理学会北海道支部学術講演会講演予稿集, 45, 08 Jan. 2009
Japanese, Summary national conference

Co₂MnSi細線電極における磁壁構造に依存したトンネル磁気抵抗のシミュレーション
澤田圭佑; 増田昌洋; 植村哲也; 松田健一; 山本眞史, 第44回応用物理学会北海道支部学術講演会講演予稿集, 46, 08 Jan. 2009
Japanese, Summary national conference

Co₂Cr_0.6Fe_0.4Al/MgO/Co₅₀Fe₅₀強磁性トンネル接合のコンダクタンス特性に対するアニールの影響
米村和希; 板橋直樹; 松田健一; 植村哲也; 山本眞史, 第44回応用物理学会北海道支部学術講演会講演予稿集, 39, 08 Jan. 2009
Japanese, Summary national conference

ホイスラー合金薄膜を上部フリー層に用いた微細MTJの作製と評価
増田昌洋; 澤田圭佑; 植村哲也; 松田健一; 山本眞史, 第44回応用物理学会北海道支部学術講演会講演予稿集, 44, 08 Jan. 2009
Japanese, Summary national conference

Fabrication of fully epitaxial magnetic tunnel junctions with half-metallic Heusler alloy thin films and a MgO tunnel barrier
M. Yamamoto; T. Uemura; K.-i. Matusda, The 10th Int’l Joint Symposium between Hokkaido University and Chungnam National University, vol.10, Oct. 2008
English, Summary international conference

Co₂MnSi電極を用いた強磁性トンネル接合におけるスピン依存コンダクタンス特性
石川貴之; 板橋直樹; 平智幸; 松田健一; 植村哲也; 山本眞史, 第32回日本磁気学会学術講演会講演概要集, 170, 12 Sep. 2008
Japanese, Summary national conference

Co₂MnGe/MgO/Co₅₀Fe₅₀強磁性トンネル接合のトンネル磁気抵抗特性の改善
平智幸; 石川貴之; 松田健一; 植村哲也; 山本眞史, 第32回日本磁気学会学術講演会講演概要集, 172, 12 Sep. 2008
Japanese, Summary national conference

Co₂Cr_0.6Fe_0.4Al/MgO/Co₂Cr_0.6Fe_0.4Al強磁性トンネル接合のスピン依存トンネルスペクトロスコピー
板橋直樹; 石川貴之; 松田健一; 植村哲也; 山本眞史, 第32回日本磁気学会学術講演会講演概要集, 285, 12 Sep. 2008
Japanese, Summary national conference

Co₂MnGe/MgO/Co₅₀Fe₅₀強磁性トンネル接合のコンダクタンス特性
平智幸; 石川貴之; 松田健一; 植村哲也; 山本眞史, 2008年秋季第69回応用物理学会学術講演会講演予稿集, 2, 666, 02 Sep. 2008
Japanese, Summary national conference

Nb/PdNi二層膜およびNb/PdNi/Nbジョセフソン接合の電気伝導特性
松田健一; 秋元陽介; 植村哲也; 山本眞史, 2008年秋季第69回応用物理学会学術講演会講演予稿集, 1, 258, 02 Sep. 2008
Japanese, Summary national conference

Co₂MnSi/MgO/Co₂MnSi MTJのスピン依存トンネル特性に対するアニール効果
石川貴之; 板橋直樹; 平智幸; 松田健一; 植村哲也; 山本眞史, 2008年秋季第69回応用物理学会学術講演会講演予稿集, 2, 655, 02 Sep. 2008
Japanese, Summary national conference

Co₂Cr_0.6Fe_0.4Al/MgO/Co₅₀Fe₅₀強磁性トンネル接合のスピン依存トンネル特性
米村和希; 石川貴之; 松田健一; 植村哲也; 山本眞史, 2008年秋季第69回応用物理学会学術講演会講演予稿集, 2, 654, 02 Sep. 2008
Japanese, Summary national conference

Co₂MnSi/MgO/Co₂MnSi強磁性トンネル接合のコンダクタンス特性
板橋直樹; 石川貴之; 松田健一; 植村哲也; 山本眞史, 2008年春季第55回応用物理学関係連合講演会講演予稿集, 2, 786, 27 Mar. 2008
Japanese, Summary national conference

エピタキシャル強磁性トンネル接合におけるCo₂MnSi電極のハーフメタル特性
石川貴之; 板橋直樹; 松田健一; 植村哲也; 山本眞史, 2008年春季第55回応用物理学関係連合講演会講演予稿集, 2, 786, 27 Mar. 2008
Japanese, Summary national conference

Formation and Orientation of Bacterial Cellulose Fibril Cultured on Solid/Liquid Interface
PUTRA ANANDA; KAKUGO AKIRA; FURUKAWA HIDEMITSU; GONG JIAN PING; OSADA YOSHIHITO; UEMURA TETSUYA; YAMAMOTO MASAFUMI, 第42回高分子学会北海道支部研究発表会講演要旨集, 51, 29 Jan. 2008
English, Summary national conference

Co₂MnSi/MgO強磁性トンネル接合におけるスピン依存トンネル抵抗のバイアス電圧依存性
板橋直樹; 石川貴之; 松田健一; 植村哲也; 山本眞史, 第43回応用物理学会北海道支部学術講演会講演予稿集, 51, 10 Jan. 2008
Japanese, Summary national conference

ホイスラー合金Co₂MnZ(Z=Si,Ge)薄膜を用いた強磁性トンネル接合におけるトンネル磁気抵抗特性の薄膜組成依存性
袴田真矢; 石川貴之; 松田健一; 植村哲也; 山本眞史, 第43回応用物理学会北海道支部学術講演会講演予稿集, 49, 10 Jan. 2008
Japanese, Summary national conference

Nb/強磁性体PdNi/Nbジョセフソン接合の電流‐電圧特性の温度依存性および強磁性膜厚依存性
秋元陽介; 松田健一; 植村哲也; 山本眞史, 第43回応用物理学会北海道支部学術講演会講演予稿集, 4, 10 Jan. 2008
Japanese, Summary national conference

CoFe/MgO/CoFe強磁性トンネル接合におけるトンネル磁気抵抗のMgOバリア膜厚に対する振動的依存性
平智幸; 石川貴之; 袴田真矢; 松田健一; 植村哲也; 山本眞史, 第43回応用物理学会北海道支部学術講演会講演予稿集, 50, 10 Jan. 2008
Japanese, Summary national conference

GaAs上に成長したCo₂MnSi薄膜の構造および磁気特性に対するMgO層挿入の効果
今井洋介; 河岸沙織; 植村哲也; 松田健一; 山本眞史, 第43回応用物理学会北海道支部学術講演会講演予稿集, 54, 10 Jan. 2008
Japanese, Summary national conference

ホイスラー合金Co₂Cr_0.6Fe_0.4Al/MgO/Co₅₀Fe₅₀強磁性トンネル接合におけるスピン依存トンネル抵抗のMgOバリア膜厚に対する振動的依存性
米村和希; 石川貴之; 松田健一; 植村哲也; 山本眞史, 第43回応用物理学会北海道支部学術講演会講演予稿集, 52, 10 Jan. 2008
Japanese, Summary national conference

ホイスラー合金Co₂MnSi薄膜を用いた強磁性トンネル接合型磁気センサーの製作と評価
増田昌洋; 植村哲也; 松田健一; 山本眞史, 第43回応用物理学会北海道支部学術講演会講演予稿集, 53, 10 Jan. 2008
Japanese, Summary national conference

エピタキシャルCo₂MnSi/MgO/n‐GaAsトンネル接合の特性評価
河岸沙織; 今井洋介; 植村哲也; 松田健一; 山本眞史, 第43回応用物理学会北海道支部学術講演会講演予稿集, 47, 10 Jan. 2008
Japanese, Summary national conference

Co₂MnSi/MgO/Co₂MnSiエピタキシャル強磁性トンネル接合のトンネル磁気抵抗特性
石川貴之; 袴田真矢; 松田健一; 植村哲也; 山本眞史, 第43回応用物理学会北海道支部学術講演会講演予稿集, 48, 10 Jan. 2008
Japanese, Summary national conference

Tubular Bacterial Cellulose Gel with Oriented Fibrils on the Curved Surface
A. Putra; A. Kakugo; H. Furukawa; J. P. Gong; Y. Osada; T. Uemura; M. Yamamoto, Polymer, 49, 7, 1885, 1891, Jan. 2008

Co₂MnZ(Z=Si,Ge)/MgO/Co₅₀Fe₅₀強磁性トンネル接合のTMR特性の薄膜組成依存性
袴田真矢; 石川貴之; 松田健一; 植村哲也; 山本眞史, 第31回日本応用磁気学会学術講演会講演概要集, 36, 11 Sep. 2007
Japanese, Summary national conference

ホイスラー合金MTJにおけるスピン依存トンネル抵抗のMgOバリア膜厚に対する振動的依存性
丸亀孝生; 石川貴之; 米村和希; 松田健一; 植村哲也; 山本眞史, 第31回日本応用磁気学会学術講演会講演概要集, 39, 11 Sep. 2007
Japanese, Summary national conference

MgO障壁と界面を形成するホイスラー合金Co₂MnSiエピタキシャル極薄膜のXASおよびXMCD
齊藤敏明; 片山利一; 石川貴之; 山本眞史; 植村哲也; 浅野裕司; 江村藍; 角田乃亜; 松岡七絵; 朝倉大輔; 小出常晴, 第31回日本応用磁気学会学術講演会講演概要集, 42, 11 Sep. 2007
Japanese, Summary national conference

Co₂MnSi薄膜を用いた強磁性トンネル接合型磁気センサーの製作
植村哲也; 増田昌洋; 松田健一; 山本眞史, 第31回日本応用磁気学会学術講演会講演概要集, 38, 11 Sep. 2007
Japanese, Summary national conference

Co₂MnSi/MgO/Co₂MnSi強磁性トンネル接合の製作とトンネル磁気抵抗特性
石川貴之; 袴田真矢; 平智幸; 松田健一; 植村哲也; 山本眞史, 第31回日本応用磁気学会学術講演会講演概要集, 37, 11 Sep. 2007
Japanese, Summary national conference

CoFe/MgO/CoFe強磁性トンネル接合におけるトンネル磁気抵抗のMgOバリア膜厚依存性
平智幸; 石川貴之; 袴田真矢; 松田健一; 植村哲也; 山本眞史, 2007年秋季第68回応用物理学会学術講演会講演予稿集, 1, 491, 04 Sep. 2007
Japanese, Summary national conference

GaAs上にMgO層を介して成長したCo₂MnSi薄膜の構造および磁気特性評価
今井洋介; 河岸沙織; 松田健一; 植村哲也; 山本眞史, 2007年秋季第68回応用物理学会学術講演会講演予稿集, 1, 475, 04 Sep. 2007
Japanese, Summary national conference

Co₂MnSi薄膜を上部フリー層に用いたエピタキシャルMTJの製作と評価
増田昌洋; 植村哲也; 松田健一; 山本眞史, 2007年秋季第68回応用物理学会学術講演会講演予稿集, 1, 475, 04 Sep. 2007
Japanese, Summary national conference

Co₂MnSiを用いたエピタキシャル強磁性トンネル接合におけるTMR特性の薄膜組成依存性
石川貴之; 丸亀孝生; 袴田真矢; 松田健一; 植村哲也; 山本眞史, 2007年春季第54回応用物理学関係連合講演会講演予稿集, 1, 512, 27 Mar. 2007
Japanese, Summary national conference

ホイスラー合金Co₂MnGe薄膜を用いた強磁性トンネル接合のTMR特性の改善
袴田真矢; 石川貴之; 丸亀孝生; 松田健一; 植村哲也; 山本眞史, 2007年春季第54回応用物理学関係連合講演会講演予稿集, 1, 513, 27 Mar. 2007
Japanese, Summary national conference

4値状態を有するCoFe/MgO/CoFeエピタキシャル強磁性トンネル接合の製作
植村哲也; 丸亀孝生; 松田健一; 山本眞史, 2007年春季第54回応用物理学関係連合講演会講演予稿集, 1, 530, 27 Mar. 2007
Japanese, Summary national conference

Co₂Cr_0.6Fe_0.4Al/MgO/Co₂Cr_0.6Fe_0.4Alエピタキシャル強磁性トンネル接合の製作
丸亀孝生; 石川貴之; 袴田真矢; 松田健一; 植村哲也; 山本眞史, 2007年春季第54回応用物理学関係連合講演会講演予稿集, 1, 514, 27 Mar. 2007
Japanese, Summary national conference

Magnetic and transport properties of Nb/Pd0.85Ni0.15 bilayer structures
H. Niwa; K. Matsuda; Y. Akimoto; T. Uemura; M. Yamamoto, The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.4, p.50, AP-08, Mar. 2007
English, Summary international conference

Epitaxial growth and characterization of Co2Cr0.6Fe0.4Al thin films on GaAs with MgO interlayer
T. Yano; T. Uemura; K. Matsuda; M. Yamamoto, The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Sapporo, Collected Papers, vol.4, p.49, DD-07, Mar. 2007
English, Summary international conference

Fabrication of magnetic tunnel junction field sensors using a Co2MnSi thin film
S. Yasuda; M; Masuda; T. Uemura; M. Yamamoto, The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.4, p.48, Mar. 2007
English, Summary international conference

Spin-dependent tunneling in fully epitaxial Co2MnSi/MgO/Co50Fe50 magnetic tunnel junctions
T. Ishikawa; T. Marukame; K.-i. Matsuda; T. Uemura; M. Yamamoto, The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.4, p.46, Mar. 2007
English, Summary international conference

Spin-polarized tunneling in fully epitaxial magnetic tunnel junctions with a full-Heusler alloy thin film
M. Yamamoto; T. Uemura; K.-i. Matsuda, The 4th Int’l Symposium on Ubiquitous Knowledge Network Environment, Collected Papers, vol.4, pp.131-145, Mar. 2007, [Invited]
English, Summary international conference

19aRD-3 Transport properties of superconducting variable-thickness bridges with Superconductor/Ferromagnet bilayer structure
Matsuda K.-i.; Niwa H.; Akimoto Y.; Uemura T.; Yamamoto M., Meeting abstracts of the Physical Society of Japan, 62, 1, 773, 773, 28 Feb. 2007
The Physical Society of Japan (JPS), Japanese

Fabrication of epitaxial magnetic tunnel junctions with a Heusler alloy Co_2Cr_<0.6>Fe_<0.4>Al thin film and a MgO tunnel barrier and their tunnel magnetoresistance characteristics
MARUKAME Takao; ISHIKAWA Takayuki; MATSUDA Ken-ichi; UEMURA Tetsuya; YAMAMOTO Masafumi, IEICE technical report, 106, 520, 51, 56, 25 Jan. 2007
Fully epitaxial magnetic tunnel junctions (MTJs) were fabricated with a full-Heusler alloy Co_2Cr_<0.6>Fe_<0.4>Al (CCFA) thin film and a MgO tunnel barrier. Pseudo-spin-valve-type, fully epitaxial CCFA/MgO/Co_<50>Fe_<50> MTJs with a CCFA film composition close to the stoichiometric one demonstrated high tunnel magnetoresistance (TMR) ratios of 90% at room temperature (RT) and 240% at 4.2 K. From this result, it was suggested that the CCFA film composition close to stoichiometric one is essential for obtaining high spin polarizations in CCFA thin films. The fully epitaxial CCFA/MgO/Co_<50>Fe_<50> MTJs with exchange biasing, where a Co_<50>Fe_<50> upper electrode was used in a synthetic ferrimagnetic Co_<50>Fe_<50>/Ru/Co_<90>Feio trilayer exchange-biased with an IrMn layer through the Co_<90>Feio/IrMn interface, exhibited high TMR ratios of 109% at RT and 317% at 4.2 K. From the obtained TMR ratio of 317% at 4.2 K, a high tunneling spin polarization of 0.88 at 4.2 K was estimated for epitaxial CCFA films with the B2 structure. These results confirm the promise of an epitaxial MTJ using a Co-based full-Heusler alloy as a key device structure for utilizing the potentially high spin polarization of this material system., The Institute of Electronics, Information and Communication Engineers, Japanese

Non-volatile Ternary Content Addressable Memory using CoFe-based Magnetic Tunnel Junction
UEMURA TETSUYA; MARUKAME TAKAO; MATSUDA KEN'ICHI; YAMAMOTO MASAFUMI, 電子情報通信学会技術研究報告, 106, 521(SDM2006 228-244), 57, 62, 25 Jan. 2007
An epitaxial Co_<50>Fe_<50>/MgO/Co_<50>Fe_<50> magnetic tunnel junction (MTJ) was fabricated and a relatively high tunnel magnetoresistance (TMR) ratio of 145% at room temperature (RT) was obtained. Four remanent magnetization states in the single-crystalline Co5oFe50 electrode, due to the cubic anisotropy with easy axes of the (110) directions, result in four possible angular-dependent TMRs, each separated by more than 20% at RT. Analysis of the asteroid curve for Co_<50>Fe_<50> indicated that the magnetic field along 22.5°from the <110> directions made it possible to change the magnetization direction of the selected cell without disturbing those of the half-selected cells. Furthermore, a ternary content addressable memory (TCAM) using the multi-state MTJ was proposed and its operation was analyzed through circuit simulation. In addition to the non-volatility, the proposed TCAM has an advantage to reducing the device count to 1/3 of that for conventional CMOS-based TCAM., The Institute of Electronics, Information and Communication Engineers, Japanese, Summary national conference

Synthesis and Characterization of Bacterial Cellulose Gel with Well oriented Fibers
PUTRA ANANDA; KAKUGO AKIRA; FURUKAWA HIDEMITSU; GONG JIAN PING; OSADA YOSHIHITO; UEMURA TETSUYA; YAMAMOTO MASAFUMI, 第18回高分子ゲル研究討論会講演要旨集, 5, 6, 19 Jan. 2007
English, Summary national conference

強磁性体‐超伝導体2層薄膜における超伝導転移温度の強磁性膜厚依存性と電気伝導特性
松田健一; 丹羽浩貴; 秋元陽介; 植村哲也; 山本眞史, 第42回応用物理学会北海道支部学術講演会講演予稿集, 44, 11 Jan. 2007
Japanese, Summary national conference

Co₂MnSi薄膜とMgOバリアを用いた交換バイアス型エピタキシャルMTJの製作と評価
石川貴之; 丸亀孝生; 袴田真也; 松田健一; 植村哲也; 山本眞史, 第42回応用物理学会北海道支部学術講演会講演予稿集, 47, 11 Jan. 2007
Japanese, Summary national conference

GaAs基板上にスパッタ成長したCo₂Cr_0.6Fe_0.4Al薄膜の評価
矢野敏史; 植村哲也; 松田健一; 山本眞史, 第42回応用物理学会北海道支部学術講演会講演予稿集, 41, 11 Jan. 2007
Japanese, Summary national conference

Improved tunnel magnetoresistance characteristics of magnetic tunnel junctions with a Heusler alloy thin film of Co2 MnGe and a MgO tunnel barrier
Shinya Hakamata; Takayuki Ishikawa; Takao Marukame; Ken-Ichi Matsuda; Tetsuya Uemura; Masashi Arita; Masafumi Yamamoto, Journal of Applied Physics, 101, 9, p.47, 2007
English, Summary international conference

Highly spin-polarized tunneling in fully epitaxial Co2Cr 0.6Fe0.4Al/MgO/Co50Fe50 magnetic tunnel junctions with exchange biasing
Takao Marukame; Takayuki Ishikawa; Shinya Hakamata; Ken-Ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto, Applied Physics Letters, 90, 1, p.45, DD-07, 2007
English, Summary international conference

ハーフメタル系ホイスラー合金薄膜を用いたエピタキシャル強磁性トンネル接合の製作
山本眞史; 丸亀孝生; 石川貴之; 松田健一; 植村哲也, 第114回表面技術協会講演大会講演要旨集, 332, 335, 25 Sep. 2006
Japanese, Summary national conference

Nb/Pd_0.85Ni_0.152層構造を用いた膜厚可変型ブリッジにおける超伝導近接効果
丹羽浩貴; 松田健一; 秋元陽介; 植村哲也; 山本眞史, 2006年秋季第67回応用物理学会学術講演会講演予稿集, 1, 245, 29 Aug. 2006
Japanese, Summary national conference

Co₂MnSi薄膜を用いたエピタキシャルMTJにおけるスピン依存コンダクタンス特性
丸亀孝生; 石川貴之; 木嶋飛元; 松田健一; 植村哲也; 山本眞史, 2006年秋季第67回応用物理学会学術講演会講演予稿集, 1, 430, 29 Aug. 2006
Japanese, Summary national conference

Co₂Cr_0.6Fe_0.4Al薄膜とMgOバリアを用いた交換バイアス型エピタキシャルMTJの製作
石川貴之; 丸亀孝生; 袴田真矢; 松田健一; 植村哲也; 山本眞史, 2006年秋季第67回応用物理学会学術講演会講演予稿集, 1, 430, 29 Aug. 2006
Japanese, Summary national conference

Design and analysis of magnetic random access memory consisting of magnetic tunnel junction and tunnel diode
T. Uemura; M. Yamamoto, 15th Int’l Workshop on Post-Binary ULSI Systems, Proceedings, vol.15, pp.55-60, May 2006
English, Summary international conference

Fabrication of microfluidic channel integrated with MOSFET
S. Yasuda; T. Uemura; K. -i. Matsuda; M. Yamamoto, The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.3, p.69, Feb. 2006
English, Summary international conference

Magnetic and Structural Properties of Pd1-xNix Thin Films for Superconductor / Ferromagnet / Superconductor p-Josephson junction devices
H. Niwa; K.-i. Matsuda; Y. Akimoto; T. Uemura; M. Yamamoto, The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.3, p.68, Feb. 2006
English, Summary international conference

Anisotropic tunnel magneto-resistance in (Ga,Mn)As/AlAs/(Ga,Mn)As magnetic tunnel junctions
T. Sone; T. Uemura; K. ?i. Matsuda; M. Yamamoto, The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.3, p.67, Feb. 2006
English, Summary international conference

Epitaxial growth of Co2Cr0.6Fe0.4Al thin films on GaAs substrate by magnetron sputtering
T. Yano; T. Uemura; K. ?i. Matsuda; M. Yamamoto, The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.3, p.66, DD-07, Feb. 2006
English, Summary international conference

Dependence of tunnel magnetoresistance on MgO tunnel barrier thickness in epitaxial magnetic tunnel junctions using Heusler alloy thin film
W. Sekine; T. Marukame; K. ?i. Matsuda; T. Uemura; M. Yamamoto, The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.3, p.55, Feb. 2006
English, Summary international conference

Fabrication of fully epitaxial magnetic tunnel junctions using full-Heusler alloy Co2MnSi thin film
H. Koyama; H. Kijima; K. ?i. Matsuda; T. Uemura; M. Yamamoto, The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.3, p.54, Feb. 2006
English, Summary international conference

Epitaxial growth and characterization of full-Heusler alloy Co2MnGe thin films
T. Ishikawa; T. Marukame; K. ?i. Matsuda; T. Uemura; M. Yamamoto, The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.3, p.52, Feb. 2006
English, Summary international conference

Tunnel magnetoresistance characteristics of fully epitaxial magnetic tunnel junctions using Co2MnGe thin film
T. Marukame; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto, The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Collected Papers, vol.3, p.51, Feb. 2006
English, Summary international conference

Effect of ferromagnetic-layer thickness on the critical current in Nb/Pd1-xNix/Nb Josehpson p-junctions
K. -i. Matsuda; H. Niwa; Y. Akimoto; T. Uemura; M. Yamamoto, 2006 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (IV)”, Collected Abstracts, p.95, Feb. 2006
English, Summary international conference

Characterization of anisotropic tunnel magneto-resistance in (Ga,Mn)As/AlAs/(Ga,Mn)As magnetic tunnel junctions
T. Uemura; T. Sone; K; ?i. Matsuda; M. Yamamoto, 2006 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (IV)”, Collected Abstracts, p.89, Feb. 2006
English, Summary international conference

Epitaxially grown Co2MnGe thin films and application to fully epitaxial magnetic tunnel junctions
T. Marukame; T. Ishikawa; K. -i. Matsuda; T. Uemura; M. Yamamoto, 2006 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (IV)”, Collected Abstracts, p.83, Feb. 2006
English, Summary international conference

Epitaxial growth of full-Heusler alloy Co2MnSi thin films on MgO-buffered MgO sub-strates
H. Kijima; T. Ishikawa; T. Marukame; H. Koyama; K. Matsuda; T. Uemura; M. Yamamoto, INTERMAG 2006 - IEEE International Magnetics Conference, vol.3, 377, 2006
English, Summary international conference

Fabrication of fully epitaxial magnetic tunnel junctions using full-Heusler alloy Co2Cr0.6Fe0.4Al thin film and MgO tunnel barrier
T Marukame; T Kasahara; K Matsuda; T Uemura; M Yamamoto, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 44, 16-19, L521, L524, 2005
English, Summary international conference

Multilevel Magnetic Random Access Memory Consisting of Magnetic Tunnel Junction and Resonant Tunnel Diode
T. Uemura; M. Yamamoto, “Satellite Session on Quantum Nano Electronics for Meme-Media-Based Information Technologies”, 7th Hokkaido University-Seoul National University Joint Symposium, Collected Abstracts, vol.7, pp.77-78, Jul. 2004
English, Summary international conference

Epitaxial growth of Fe/MgO/Fe heterostructures by magnetron sputtering
T. Marukame; M. Yamamoto; T. Uemura; K. Matsuda, “Satellite Session on Quantum Nano Electronics for Meme-Media-Based Information Technologies”, 7th Hokkaido University-Seoul National University Joint Symposium, Collected Abstracts, vol.7, pp.71-72, Jul. 2004
English, Summary international conference

Epitaxial growth of Co2Cr0.6Fe0.4Al Heusler alloy films on MgO (001) substrate
K. Matsuda; T. Kasahara; T. Marukame; T. Uemura; M. Yamamoto, “Satellite Session on Quantum Nano Electronics for Meme-Media-Based Information Technologies”, 7th Hokkaido University-Seoul National University Joint Symposium, Collected Abstracts, vol.7, pp.69-70, Jul. 2004
English, Summary international conference

SC-11-2 Proposal and Experimental Demonstration of MRAM Cell Consisting of Magnetic Tunnel Junction and Tunnel Diode
Uemura Tetsuya; Honma Satoshi; Marukame Takao; Yamamoto Masafumi, Proceedings of the IEICE General Conference, 2004, 2, "S, 55"-"S-56", 08 Mar. 2004
The Institute of Electronics, Information and Communication Engineers, Japanese

Characterization of (La, Sr)MnO3-d Films Deposited by Magnetron Sputtering on Si Substrate
T. Uemura; K. Sekine; K. Matsuda; M. Yamamoto, 2004 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (II)”, Collected Abstracts, p.151, Feb. 2004
English, Summary international conference

Demonstration of Functional Magnetic Tunnel Junction with Negative Differential Resistance
T. Uemura; S. Honma; T. Marukame; M. Yamamoto, 2004 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (II)”, Collected Abstracts, p.150, Feb. 2004
English, Summary international conference

Preparation and characterization of Co2Cr0.6Fe0.4Al Heusler alloy thin films grown on MgO substrate by magnetron sputtering
T. Kasahara; K. Matsuda; T. Marukame; T. Uemura; M. Yamamoto, 2004 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (II)”, Collected Abstracts, p.144, Feb. 2004
English, Summary international conference

Proposal and Experimental Demonstration of MRAM Cell Consisting of Magnetic Tunnel Junction and Negative Differential Resistance Device
UEMURA Tetsuya; HONMA Satoshi; MARUKAME Takao; YAMAMOTO Masafumi, Technical report of IEICE. SDM, 103, 631, 41, 46, 23 Jan. 2004
Two kinds of novel magnetic random access memory (MRAM) cells, which consist of a magnetic tunnel junction (MTJ) and a tunnel diode connected in parallel or in series, are proposed. Their basic operations were successfully confirmed by both simulation and experiment. The negative differential resistance (NDR) characteristics of the tunnel diode can increase the tunneling magnetoresistance (TMR) ratio of the MTJ. The fabricated circuit consisting of the CoFe based double junction MTJ and GaAs based tunnel diode showed that the effective MR ratio was enhanced from its original value of 15 to 890%. In the simulation, a sufficient operating margin of the bias current/voltage was obtained by using the MTJ with its original TMR ratio of more than 30%., The Institute of Electronics, Information and Communication Engineers, Japanese

Analysis of a Triple Barrier Structure Consisting of Ferromagnetic and Non-magnetic Quantum Wells
T. Marukame; T. Uemura; M. Yamamoto, 2003 RCIQE Int. Seminar on “Quantum Nanoelectronics for Meme-Media-Based Information Technologies”, Collected Abstracts, p.128, Feb. 2003
English, Summary international conference

Multiple-Valued T-Gate Based on Multiple Junction Surface Tunnel Transistor
UEMURA Tetsuya; BABA Toshio, IEICE transactions on electronics, 85, 7, 1486, 1490, 01 Jul. 2002
A novel multiple-valued transfer gate (T-gate) consisting of multiple-junction surface tunnel transistors (MJSTTs) and hetero-junction FETs (HJFETs) was developed and its operation was confirmed by both simulation and experiment. The number of the devices required to form the T-gate can be drastically reduced because of the high functionality of the MJSTT; namely only three MJSTTs and three HJFETs are required to fabricate the three-valued T-gate. This number of transistors is less than half that of a conventional circuit. The fabricated circuit exhibited abasic T-gate operation with various logic functions. Furthermore, only one T-gate is needed to form a multiple-valued D-flip-flop (D-FF) circuit., The Institute of Electronics, Information and Communication Engineers, English

A Three-valued Shift Register based on Multiple Junction Surface Tunnel Transistors
Uemura Tetsuya; Baba Toshio, Proceedings of the IEICE General Conference, 2001, 2, 82, 82, 07 Mar. 2001
The Institute of Electronics, Information and Communication Engineers, Japanese

Self-Aligned Surface Tunnel Transistor with 80nm Gate Length
CHUN Yong Jin; UEMURA Tetsuya; BABA Toshio, IEICE technical report. Electron devices, 100, 642, 21, 26, 22 Feb. 2001
A novel method using electron-beam (EB) lithography and regrowth for fabricating self-aligned InGaAs-based surface tunnel transistors (STTs) with sub-micron gate lengths has been developed. The shape of regrowth layer on the gate region is significantly affected not only by the gate lengths but also by the thickness of the regrowth layer. During regrowth, (111) facets are formed at the edges of the gate region while the (100) surface is maintained at the center. The shape changes to triangular consisting of (111) facets as gate length decreases below 150 nm due to the slow growth rate of the (111) facets compared to the (100) surface. The 80 nm STTs were fabricated by controlling the shape of the regrowth layer, and no deposition of the regrowth layer on the sidewall, which causes leakage current, occurred. The successful operation of InGaAs-based 80 nm STTs with clear negative differential resistance (NDR) characteristics and a gate-controlled peak current was obtained at room temperature., The Institute of Electronics, Information and Communication Engineers, Japanese

A Three-valued T-gate and Two-stage D-FF Circuits using Multiple-junction Surface Tunnel Transistors and Hetero-junction FET
Uemura Tetsuya; Baba Toshio, Proceedings of the Society Conference of IEICE, 2000, 2, 167, 168, 07 Sep. 2000
The Institute of Electronics, Information and Communication Engineers, Japanese

Demonstration of a Novel Multiple-valued T-gate using Multiple Junction Surface Tunnel Transistors and Its Application to Three-valued Data Flip-Flop
UEMURA Tetsuya; BABA Toshio, IEICE technical report. Electron devices, 100, 147, 67, 72, 21 Jun. 2000
A novel T-gate, the most useful logic gate in the multiple valued logic circuits, consisting of multi-junction surface tunnel transistors(MJSTTs)and FETs were proposed and its operation was successfully confirmed by both simulation and experiment. The number of the devices required for the T-gate can be drastically reduced due to a high functionality of the MJ-STT. Only three MJSTTs and three FETs were required to fabricate the three-valued T-gate, whose number is less than one half of that of the conventional circuit. The fabricated circuit exhibited a basic T-gate operation with various logic functions. Furthermore, a multiple-valued data Flip-Flop(D-FF) circuit could be realized by only one T-gate., The Institute of Electronics, Information and Communication Engineers, English

A Three-valued T-gate Circuit using Multiple Junction Surface Tunnel Transistors
Uemura Tetsuya; Baba Toshio, Proceedings of the IEICE General Conference, 2000, 2, 59, 59, 07 Mar. 2000
The Institute of Electronics, Information and Communication Engineers, Japanese

Surface Tunnel Transistor
Baba Toshio; Uemura Tetsuya, Proceedings of the Society Conference of IEICE, 1997, 2, 175, 176, 13 Aug. 1997
我々は、微細化に適する新しい量子効果素子として半導体中のバンド間トンネル電流を直接ゲート電極により制御する表面トンネル卜ランジスタ(STT, Surface Tunnel Transistor)を提案している。これまでにGaAs系素子試作によりその動作を確認しているが、実用的な観点から高速動作や機能性の向上が求められている。本報告では最近の成果であるInGaAs系材料による動作電流密度の向上、多重接合STTの提案とその動作実証、および多値メモリー動作の確認を中心に、研究の現状と展望について述べる。, The Institute of Electronics, Information and Communication Engineers, Japanese

Surface Tunnel Transistors with Multiple Interband Tunnel Junctions
BABA Toshio; UEMURA Tetsuya, IEICE transactions on electronics, 80, 7, 875, 880, 25 Jul. 1997
New functional surface tunnel transistors (STTs) with multiple interband-tunnel-junctions in a symmetric source-to-drain structure are proposed to reduce the number of fabrication steps and to increase functionality. These devices have p^+/n^+ interband tunnel junctions in series between a p^+ source and a p^+ drain through n^+ channels. We successfully fabricated GaAs-based multiple-junction STTs (MJ-STTs) using molecular-beam epitaxy regrowth. This fabrication method eliminates the need for two of the photo-masks in the conventional process for asymmetric planar STTs. In the preliminary experiments using multiple-junction p^+/n^+ diodes, we found that the peak-voltage increment in negative-differential-resistance (NDR) characteristics due to the reverse-biased tunnel junction is negligible, while the first-peak voltage is roughly proportional to the number of forward-biased tunnel junctions. Moreover, the number of NDR characteristics are completely determined by the number of tunnel junctions. The fabricated STTs with multiple junctions, up to eight junctions, exhibited clear transistor operation with multiple NDR characteristics, which were symmetric with the drain bias. These results indicate that any number of gate-controlled NDR characteristics can be realized in MJ-STTs by using an appropriate number of tunnel junctions in series. In addition, as an example of a functional circuit using MJ-STTs, we implemented a tri-stable circuit with a four-junction STT and a load resistor connected in series. The tri-stable operation was confirmed by applying a combination of a reset pulse and a set pulse for each stable point., The Institute of Electronics, Information and Communication Engineers, English

Characterization for negative differential esistance in Surface Tunnel Transistor.
Uemura Tetsuya; Baba Toshio, IEICE technical report. Electron devices, 94, 22, 47, 53, 22 Apr. 1994
In order to improve the device performance of the Surface Tunnel Transistor(STT),we fabricated a new structure in which the channel region was directly doped with donors to increase the degeneracy of the conduction band in the channel.As a result,a 10^3 times larger drain current than the conventional one and a clear gate- controlled negative differential resistance(NDR)due to interband tunnering at room temperature were obtained in the fabricated STT. Moreover,to demonstrate application as a functional device,a bistable circuit consisting of only one STT and one load resistor was organized and its operation was confrmed.In order to clarify the origin of the valley current,we fabricated p^+-n^+ tunnel diodes with the same regrown interface as the STT,and investigated the dependence of the NDR characteristics on both the impurity concentration at the regrown interface and the temperature.These measurements indicate that the valley current is mainly caused by the excess tunneling current through traps formed by the residual oxygen at the regrown interface., The Institute of Electronics, Information and Communication Engineers, Japanese

■ Books and other publications

Heusler Alloys
M. Yamamoto; T. Uemura, Chap. 18
Springer International Publishing Switzerland, Jan. 2016, 486, 413-444, English, Scholarly book, [Joint work]

■ Lectures, oral presentations, etc.

Spin injection into semiconductor and current-induced domain wall motion using Co-based ferromagnet
Tetsuya Uemura; Michihiko Yamanouchi
Physics and Application of Spatial structures on Spin, QuAntum state and Light (PASSQAL-1), Oct. 2024, English
Oct. 2024 - Oct. 2024, [Invited]

Coherent manipulation of nuclear spins in GaAs using electrical spin injection
T. Uemura
International Workshop on NanoScience and NanoOptics 2017, 02 Nov. 2017, English, Invited oral presentation
02 Nov. 2017 - 03 Nov. 2017, [Invited]

Coherent Control of Nuclear Spins in Semiconductor using Electrical Spin Injection
UEMURA Tetsuya
2016 RCIQE International Seminar, 08 Mar. 2016, English, Invited oral presentation
[Invited], [International presentation]

Half-metallic Heusler alloys for the spin sources of spintronic devices
Masafumi Yamamoto; Tetsuya Uemura
13th RIEC International Workshop on Spintronics, 18 Nov. 2015, English, Invited oral presentation
[Invited], [International presentation]

Manupulation of nuclear spins in GaAs using a half-metallic spin source of Co2MnSi
T. Uemura; M. Yamamoto
IEEE Int’l Magnetics Conf. 2015, 11 May 2015, English, Invited oral presentation
[Invited], [International presentation]

Temperature dependence of spin-dependent tunneling resistance of Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
Y. Honda; H.-x. Liu; T. Uemura; M. Yamamoto
49th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Dec. 2013, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Demonstration of high spin injection efficiency in Co2MnSi/CoFe/n-GaAs junctions
Y. Ebina; T. Akiho; H.-x. Liu; M. Yamamoto; T. Uemura
49th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Dec. 2013, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Spin lifetime in strained InGaAs channels investigated through all electrical spin injection and detection
T. Akiho; M. Yamamoto; T. Uemura
The 18th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-18), Dec. 2013, English, Oral presentation
Osaka Univ., Toyonaka, [Domestic Conference]

Effect of CoFe insertion on spin injection properties of Co2MnSi/CoFe/n-GaAs junctions
Y. Ebina; T. Akiho; H. Liu; M. Yamamoto; T. Uemura
58th Annual Conference on Magnetism and Magnetic Materials, Nov. 2013, English
Denver, Colorado, USA, [International presentation]

Giant tunnel magnetoresistance in fully epitaxial Co2(Mn,Fe)Si/MgO/Co2(Mn,Fe)Si magnetic tunnel junctions
T. Kawami; H. Liu; Y. Honda; K. M. Ayele; T. Uemura; F. Shi; P. M. Voyles; M. Yamamoto
58th Annual Conference on Magnetism and Magnetic Materials, Nov. 2013, English
Denver, Colorado, USA, [International presentation]

Spin and symmetry properties of the buried Co2MnSi/MgO interface.
R. Fetzer; Y. Ohdaira; H. Naganuma; M. Oogane; Y. Ando; T. Taira; T. Uemura; M. Yamamoto; M. Aeschlimann; M. Cinchetti
58th Annual Conference on Magnetism and Magnetic Materials, Nov. 2013, English
Denver, Colorado, USA, [International presentation]

Spin-dependent transport properties of strained InGaAs channel investigated through all electrical spin injection and detection
T. Akiho; M. Yamamoto; T. Uemura
58th Annual Conference on Magnetism and Magnetic Materials, Nov. 2013, English
Denver, Colorado, USA, [International presentation]

Dynamic nuclear polarization observed in Co2MnSi/CoFe/n-GaAs heterojunctions
T. Akiho; H.-x. Liu; M. Yamamoto; T. Uemura
The 37th Annual Conference on Magnetics in Japan 2013, Sep. 2013, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Effect of CoFe insertion on spin injection properties in Co2MnSi/CoFe/n-GaAs junctions
Y. Ebina; T. Akiho; H.-x. Liu; M. Yamamoto; T. Uemura
The 37th Annual Conference on Magnetics in Japan 2013, Sep. 2013, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Giant tunneling magnetoresistance in fully epitaxial Co2(Mn, Fe)Si/MgO/ Co2(Mn, Fe)Si magnetic tunnel junctions
T. Kawami; H.-x. Liu; Y. Honda; T. Uemura; F.-y. Shi; P. M. Voyles; M. Yamamoto
The 37th Annual Conference on Magnetics in Japan 2013, Sep. 2013, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Effect of nonstoichiometry on the half-metallicity of Co2MnSi thin films with various Mn compositions
Y. Honda; G.-f. Li; H.-x. Liu; M. Arita; K.-i. Matsuda; T. Uemura; M. Yamamoto; T. Saito; Y. Miura; M. Shirai
The 37th Annual Conference on Magnetics in Japan 2013, Sep. 2013, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Highly-efficient dynamic nuclear polarization in GaAs using a Heusler-alloy spin source
T. Akiho; H.-x. Liu; K.-i. Matsuda; M. Yamamoto; T. Uemura
The 74th Autumn Meeting 2013, The Japan Society of Applied Physics, Sep. 2013, English, Oral presentation
Doushisha University, Kyotanabe, [Domestic Conference]

Giant tunneling magnetoresistance in fully epitaxial Co2(Mn, Fe)Si/MgO/ Co2(Mn, Fe)Si magnetic tunnel junctions
T. Kawami; H.-x. Liu; Y. Honda; T. Uemura; F.-y. Shi; P. M. Voyles; M. Yamamoto
The 74th Autumn Meeting 2013, The Japan Society of Applied Physics, Sep. 2013, English, Oral presentation
Doushisha University, Kyotanabe, [Domestic Conference]

Half-metallic Heusler alloy thin films for spintronic devices
M. Yamamoto; T. Uemura
The 74th Autumn Meeting 2013, The Japan Society of Applied Physics, Sep. 2013, Japanese, Keynote oral presentation
Doushisha University, Kyotanabe, [Invited], [Domestic Conference]

Annealing temperature dependence of spin signals observed inCo2MnSi/CoFe/n-GaAs through four-terminal non-local geometry
T. Akiho; J. Shan; K.-i. Matsuda; M. Yamamoto; T. Uemura
The 60th JSPS Spring Meeting, 2013, Mar. 2013, English, Oral presentation
Kanagawa Institute of Technology, Atsugi, [Domestic Conference]

Influence of interfacetermination layeron temperature dependenceof tunneling magnetoresistance of Co2MnSi/MgO-based magnetic tunnel junctions
H.-x. Liu; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto; F.-y. Shi; P. Voyles
The 60th JSPS Spring Meeting, 2013, Mar. 2013, English, Oral presentation
Kanagawa Institute of Technology, Atsugi, [Domestic Conference]

MgO thickness dependence of Hanle signal in Co2MnSi/CoFe/MgO/Si
J. Fujisawa; K.-i. Matsuda; M. Yamamoto; T. Uemura
48th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2013, Japanese, Oral presentation
Kushiro-shi Syogai Gakusyu Center “Manabotto Nusamai”, Kushiro, [Domestic Conference]

Superconducting proximity effect in Nb/Cu50Ni50 bilayers and ther transport properties
Y. Ebina; K.-i. Matsuda; T. Uemura; M. Yamamoto
48th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2013, Japanese, Oral presentation
Kushiro-shi Syogai Gakusyu Center “Manabotto Nusamai”, Kushiro, [Domestic Conference]

Spin injectioin from ferromagnet into InGaAs thfough GaAs tunnel barrier
T. Torino; K.-i. Matsuda; M. Yamamoto; T. Uemura
48th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2013, Japanese, Oral presentation
Kushiro-shi Syogai Gakusyu Center “Manabotto Nusamai”, Kushiro, [Domestic Conference]

Influence of interfacial structural properties on tunnel magnetoresistance in epitaxial magnetic tunnel junctions with Co2MnSi electrode and MgO barrier
H.-x. Liu; Y. Honda; K.-i. Matsuda; M. Arita; T. Uemura; M. Yamamoto
12th Joint MMM/Intermag Conf., Jan. 2013, English
Chicago, Illinois, USA, [International presentation]

Transient effects on oblique Hanle signals observed in ferromagnet/semiconductor heterojunctions with non-local four-terminal configuration
T. Akiho; J.-h. Shan; K.-i. Matsuda; M. Yamamoto; T. Uemura
12th Joint MMM/Intermag Conf., Jan. 2013, English
Chicago, Illinois, USA, [International presentation]

Tunnel barrier thickness dependence of Hanle signals in CoFe/MgO/SC (SC= Si or Ge) investigated through three-terminal configuration
T. Uemura; G.-f. Li; J. Fujisawa; K.-i. Matsuda; M. Yamamoto
The 17th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-17), Dec. 2012, Japanese, Oral presentation
INAMORI Frontier Center, Kyusyu Univ., Fukuoka, [Domestic Conference]

Spin injection into GaAs from highly spin-polarized ferromagnetic electrode
T. Uemura; T. Akiho; K.-i. Matsuda; M. Yamamoto
The 17th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-17), Dec. 2012, Japanese, Invited oral presentation
INAMORI Frontier Center, Kyusyu Univ., Fukuoka, [Invited], [Domestic Conference]

Electrical spin injection and electrical detection of dynamic nuclear polarization in ferromagnet/semiconductor heterojunctions
T. Akiho; J.-h. Shan; K.-i. Matsuda; M. Yamamoto; T. Uemura
International Workshop on Spintronic Nano Materials 2012, Nov. 2012, English, Invited oral presentation
Hokkaido Univ., Sapporo, Japan, [Invited], [International presentation]

Enhanced coherent tunneling contribution in epitaxial magnetic tunnel junctions with a Co2MnSi electrode and a MgO barrier due to improved interfacial structural properties
H.-x. Liu; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 2nd Int’l Conf. of Asia Union of Magnetics Societies (ICAUMS 2012), The 36th Annual Conf. on Magnetics in Japan, Oct. 2012, English
Nara Prefectural New Public Hall, Nara, Japan, [International presentation]

Co50Fe50電極からGaAs へのスピン注入の電気的検出
T. Uemura; T. Akiho; M. Harada; K.-i. Matsuda; M. Yamamoto
The 35th Annual Conference on Magnetics in Japan 2011, Sep. 2012, Japanese, Oral presentation
International conference room, Toki Messe, Niigata, [Domestic Conference]

Transient oblique Hanle signals observed in a Co2MnSi/CoFe/n-GaAs Schottky tunnel junction with non-local four-terminal configuration
Jinhai Shan; Takafumi Akiho; Ken-ichi Matsuda; Masafumi Yamamoto; Tetsuya Uemura
The 73th Autumn Meeting 2012, The Japan Society of Applied Physics, Sep. 2012, Japanese, Oral presentation
Ehime University & Matsuyama Univeristy, Matsuyama, [Domestic Conference]

MgO tunnel barrier thickness dependence of three-terminal Hanle-type signals in CoFe/MgO/n-Ge tunnel junctions
G.-f. Li; M. Miki; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 73th Autumn Meeting 2012, The Japan Society of Applied Physics, Sep. 2012, English, Oral presentation
Ehime University & Matsuyama Univeristy, Matsuyama, [Domestic Conference]

Spin-polarization measurement for Heusler alloy Co2MnSi using Co2MnSi/MgO/NbN junctions
K. ?i. Matsuda; T. Shinoki; T. Uemura; M. Yamamoto
The 73th Autumn Meeting 2012, The Japan Society of Applied Physics, Sep. 2012, Japanese, Oral presentation
Ehime University & Matsuyama Univeristy, Matsuyama, [Domestic Conference]

Temperature dependence of spin-dependent tunneling resistances of fully epitaxial Co2MnSi-based magnetic tunnel junctions
H.-x. Liu; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 73th Autumn Meeting 2012, The Japan Society of Applied Physics, Sep. 2012, English, Oral presentation
Ehime University & Matsuyama Univeristy, Matsuyama, [Domestic Conference]

Tunnel barrier thickness dependence of Hanle-type signals in CoFe/MgO/n-Ge tunnel junctions investigated through three-terminal configuration
G.-f. Li; M. Miki; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 17th Int’l Conf. on Molecular Beam Epitaxy (MBE 2012), Sep. 2012, English
Nara Prefectural New Public Hall, Nara, Japan, [International presentation]

Tunnel barrier thickness dependence of Hanle-type signals in CoFe/MgO/n-Si and CoFe/MgO/n-Ge junctions investigated through three-terminal configuration
T. Uemura; G.-f. Li; J. Fujisawa; K. Kondo; K.-i. Matsuda; M. Yamamoto
2012 Int’l Conf. on Solid State Devices and Materials (SSDM 2012), Sep. 2012, English
Kyoto International Conference Center, Kyoto, Japan, [International presentation]

Transient oblique Hanle signals observed in Co2MnSi/CoFe/n-GaAs with non-local four-terminal configuration
J.-h. Shan; T. Akiho; K.-i. Matsuda; M. Yamamoto; T. Uemura
2012 Int’l Conf. on Solid State Devices and Materials (SSDM 2012), Sep. 2012, English
Kyoto International Conference Center, Kyoto, Japan, [International presentation]

Temperature dependence of spin-dependent tunneling resistances of MgO-buffered Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
Y. Honda; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
2012 Int’l Conf. on Solid State Devices and Materials (SSDM 2012), Sep. 2012, English
Kyoto International Conference Center, Kyoto, Japan, [International presentation]

Spin-polarization measurements for Co?2MnSi using Co2MnSi/MgO/NbN epitaxial tunnel junctions
Ken-ichi Matsuda; Takaho Shinoki; Tomoyuki Taira; Tetsuya Uemura; Masafumi Yamamoto
The 19th Int’l Conf. on Magnetism (ICM2012), Jul. 2012, English
BEXCO, Busan, Korea, [International presentation]

MgO thickness dependence of spin accumulation signal in Co50Fe50/MgO/Si
T. Uemura; J. Fujisawa; K.-i. Matsuda; M. Yamamoto
Int’l Magnetics Conf. 2012 (INTERMAG 2012), May 2012, English
Vancouver Convention Center, Vancouver, Canada, [International presentation]

Electrical spin injection from Co2MnSi Heusler alloy into GaAs and electrical detection of dynamic nuclear polarization
T. Akiho; T. Uemura; K.-i. Matsuda; M. Yamamoto
Int’l Magnetics Conf. 2012 (INTERMAG 2012), May 2012, English
Vancouver Convention Center, Vancouver, Canada, [International presentation]

Temperature dependence of spin-dependent tunneling conductances of fully epitaxial Co2MnSi-based magnetic tunnel junctions
H.-x. Liu; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Magnetics Conf. 2012 (INTERMAG 2012), May 2012, English
Vancouver Convention Center, Vancouver, Canada, [International presentation]

Possibility of Superconducting Proximity Effect of Equal-spin Triplet Components in NbN/Co2Cr0.6Fe0.4Al/NbN Junctions
Ken-ichi Matsuda; Tetsuya Uemura; Masafumi Yamamoto
Int’l Conf. on Topological Quantum Phenomena (TQP2012), May 2012, English
Nagoya University, Nagoya, Japan, [International presentation]

MgO thickness dependence of spin accumulation signal in CoFe/MgO/Si
Tetsuya Uemura; Jun Fijisawa; Ken-ichi Matsuda; Masafumi Yamamoto
The 59th Spring Meeting2012, The Japan Society of Applied Physics, Mar. 2012, Japanese, Oral presentation
Waseda University, Tokyo,, [Domestic Conference]

Electrical spin injection from Co2MnSi Heusler alloy into GaAsand electrical detection of dynamic nuclear polarization
Takafumi Akiho; Tetsuya Uemura; Ken-ichi Matsuda; Masafumi Yamamoto
The 59th Spring Meeting2012, The Japan Society of Applied Physics, Mar. 2012, Japanese, Oral presentation
Waseda University, Tokyo,, [Domestic Conference]

Fabrication of fully epitaxial magnetic tunnel junctions with a Heusler alloy Co2MnSi thin film and a MgO barrier on Ge(001) substrates
G.-f. Li; T. Taira; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 59th Spring Meeting2012, The Japan Society of Applied Physics, Mar. 2012, English, Oral presentation
Waseda University, Tokyo,, [Domestic Conference]

Spin-dependent transport characteristics of epitaxial magnetic tunnel junctions of CoFe/MgO/CoFe ultrathin layer/Co2MnSi
H.-x. Liu; Y. Honda; T. Taira; K.-i. Matsuda; T. Uemura; Y. Miura; M. Shirai; M. Yamamoto
The 59th Spring Meeting2012, The Japan Society of Applied Physics, Mar. 2012, English, Oral presentation
Waseda University, Tokyo,, [Domestic Conference]

Detection of nuclear magnetic filed and spin transport in Co2MnSi/CoFe/n-GaAs structures
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto
47th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2012, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Tunnel magnetoresistance in fully epitaxial CoFe/MgO/CoFe magnetic tunnel junctions on Ge(001) substrates via a MgO interlayer
G.-f. Li; T. Taira; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
47th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2012, English, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Spin-polarization measurement for Heusler alloy Co2MnSi using Co2MnSi/MgO/NbN heterostructures
T. Shinoki; K.-i. Matsuda; T. Taira; T. Uemura; M.Yamamoto
47th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2012, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Spin-polarized transport in fully epitaxial CoFe/MgO/CoFe ultrathin layer/Co2MnSi magnetic tunnel junction
H.-x. Liu; Y. Honda; T. Taira; K.-i. Matsuda; T. Uemura; Y. Miura; M. Shirai; M.Yamamoto
47th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2012, English, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Spin transport properties of fully epitaxial magnetic tunnel junctions of CoFe/MgO/CoFe ultrathin layer/Co2MnSi
H.-x. Liu; T. Taira; Y. Honda; K. -i. Matsuda; T. Uemura; M. Yamamoto; Y. Miura; M. Shirai
5th Int’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Jan. 2012, English
Hokkaido University, Sapporo, Japan, [International presentation]

Tunnel magnetoresistance in fully epitaxial CoFe/MgO/CoFe magnetic tunnel junctions on Ge(001) substrates via a MgO interlayer
G.-f. Li; T. Taira; H.-x. Liu; K. ?i. Matsuda; T. Uemura; M. Yamamoto
5th Int’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Jan. 2012, English
Hokkaido University, Sapporo, Japan, [International presentation]

Spin injection from Co2MnSi into GaAs and detection of dynamic nuclear polarization
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto
The 16th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-16), Nov. 2011, Japanese, Oral presentation
Tokyo Institute of Technology, Tokyo, [Domestic Conference]

Non-local electrical detection of Hanle signals in Co2MnSi/Co50Fe50/n-GaAs Schottky tunnel junctions
T. Akiho; T. Uemura; H. Harada; K.-i., Matsuda; M. Yamamoto
56th Annual Conf. on Magnetism & Magnetic Materials, Nov. 2011, English
Scottsdale, Arizona, USA, [International presentation]

Almost identical oscillations in tunneling resistances as a function of barrier thickness for parallel and antiparallel configurations for fully epitaxial magnetic tunnel junctions with a MgO barrier
Y. Honda; S. Hirata; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
56th Annual Conf. on Magnetism & Magnetic Materials, Nov. 2011, English
Scottsdale, Arizona, USA, [International presentation]

Fabrication of epitaxial magnetic tunnel junctions with a Co2MnSi thin film and a MgO barrier on Ge(001) substrates via a MgO interlayer
G.-f. Li; T.Taira; H.-x. Liu; K. -i. Matsuda; T. Uemura; M. Yamamoto
56th Annual Conf. on Magnetism & Magnetic Materials, Nov. 2011, English
Scottsdale, Arizona, USA, [International presentation]

Spin-dependent transport properties of fully epitaxial magnetic tunnel junctions of CoFe/MgO/CoFe ultrathin layer/Co2MnSi
H.-x. Liu; T. Taira; Y. Honda; K. -i. Matsuda; T. Uemura; M. Yamamoto; Y. Miura; M. Shirai
56th Annual Conf. on Magnetism & Magnetic Materials, Nov. 2011, English
Scottsdale, Arizona, USA, [International presentation]

Epitaxial growth of Heusler alloy Co2MnSi thin films on Ge(001) substrates via a MgO interlayer
G.-f. Li; T. Taira; K.-i. Matsuda; M. Arita; T. Uemura; M. Yamamoto
The 35th Annual Conference on Magnetics in Japan 2011, Sep. 2011, English, Oral presentation
International conference room, Toki Messe, Niigata, [Domestic Conference]

Effect of MgO Barrier Insertion on Spin-dependent Transport Properties of CoFe/n-GaAs
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto
2011 Int’l Conf. on Solid State Devices and Materials, Sep. 2011, English
Nagoya, Japan, [International presentation]

Fabrication of fully epitaxial magnetic tunnel junctions with CoFe electrodes and a MgO barrier on Ge(001) substrates via a MgO interlayer
G.-f. Li; T. Taira; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
2011 Int’l Conf. on Solid State Devices and Materials, Sep. 2011, English
Nagoya, Japan, [International presentation]

Effect of GaAs Surface Structure on Tunneling Anisotropic Magnetoresistance in Epitaxial Co50Fe50/n-GaAs Junctions
T. Uemura; T. Akiho; M. Harada; K.-i. Matsuda; M. Yamamoto
2011 Int’l Conf. on Solid State Devices and Materials, Sep. 2011, English
Nagoya, Japan, [International presentation]

Oscillations in tunneling resistances commonly observed for the parallel and antiparallel magnetization orientations as a function of barrier thickness in epitaxial Co2MnSi/MgO/Co2MnSi MTJs
Y. Honda; S. Hirata; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 72th Autumn Meeting2011, The Japan Society of Applied Physics, Aug. 2011, Japanese, Oral presentation
Yamagata University, Yamagata, [Domestic Conference]

Spin injection from Co50Fe50 into GaAs at room temperature
Tetsuya Uemura; Takafumi Akiho; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto
The 72th Autumn Meeting2011, The Japan Society of Applied Physics, Aug. 2011, Japanese, Oral presentation
Yamagata University, Yamagata, [Domestic Conference]

Influence of MgO insertion on spin dependent transport properties ofCoFe/n-GaAs hetero junctions
Takafumi Akiho; Tetsuya Uemura; Masanobu Harada; Ken-ichi Matsuda; Masafumi Yamamoto
The 72th Autumn Meeting2011, The Japan Society of Applied Physics, Aug. 2011, Japanese, Oral presentation
Yamagata University, Yamagata, [Domestic Conference]

Structural and magnetic properties of epitaxially grown Heusler alloyCo2MnSi/MgO heterostructures on Ge(001) substrates
G.-f. Li; T. Taira; K.-i. Matsuda; M. Arita; T. Uemura; M. Yamamoto
The 72th Autumn Meeting2011, The Japan Society of Applied Physics, Aug. 2011, English, Oral presentation
Yamagata University, Yamagata, [Domestic Conference]

Electrical detection of spin injection from Co50Fe50 into GaAs at room temperature
T. Uemura; M. Harada; T. Akiho; K.-i. Matsuda; M. Yamamoto
15th Int’l Conf. on Modulated Semiconductor Structures (MSS 15), Jul. 2011, English
Tallahassee, FL, USA, [International presentation]

Oscillations in spin-dependent tunneling resistances as a function of MgO barrier thickness in epitaxial magnetic tunnel junctions with Heusler alloy Co2MnSi electrodes
Y. Honda; S. Hirata; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
5th Int’l Workshop on Spin Currents, Jul. 2011, English
Sendai, Japan, [International presentation]

Spin injection from Co50Fe50 into GaAs at room temperature
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto
5th Int’l Workshop on Spin Currents, Jul. 2011, English
Sendai, Japan, [International presentation]

Spin-dependent tunneling characteristics of Heusler alloy/MgO heterostructures
M. Yamamoto; T. Uemura; K.-i. Matsuda
5th Int’l Workshop on Spin Currents, Jul. 2011, English, Invited oral presentation
Sendai, Japan, [Invited], [International presentation]

Epitaxial growth of Heusler alloy Co2MnSi/MgO heterostructure on Ge(001) substrate
G.-f. Li; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Magnetics Conf. 2011 (INTERMAG 2011), Apr. 2011, English
Taipei, Taiwan, [International presentation]

Electrical injection and detection of spin-polarized electrons in an epitaxial Co50Fe50/n-GaAs junction
T. Uemura; M. Harada; T. Akiho; K.-i. Matsuda; M. Yamamoto
Int’l Magnetics Conf. 2011(INTERMAG 2011), Apr. 2011, English
Taipei, Taiwan, [International presentation]

Spin-dependent transport properties of Co2MnSi/MgO/n-GaAs tunnel junctions
T. Akiho; M. Harada; T. Uemura; K.-i. Matsuda; M. Yamamoto
Int’l Magnetics Conf. 2011 (INTERMAG 2011), Apr. 2011, English
Taipei, Taiwan, [International presentation]

Pronounced oscillations in spin-dependent tunneling resistances of epitaxial MTJswith Co2MnSi electrodes and a MgO barrier
Y. Honda; S. Hirata; G.-f. Li; H.-x. Liu; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 58th Spring Meeting2011, The Japan Society of Applied Physics, Mar. 2011, Japanese, Oral presentation
Kanagawa Institute of Technology, Atsugi, [Domestic Conference]

Epitaxial growth of Co2MnSi/MgO heterostructures on Ge(001) substrates
G.-f. Li; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 58th Spring Meeting2011, The Japan Society of Applied Physics, Mar. 2011, English, Oral presentation
Kanagawa Institute of Technology, Atsugi, [Domestic Conference]

Electrical detection of spin injection in Co50Fe50/n-GaAs
T. Uemura; M. Harada; T. Akiho; K.-i. Matsuda; M. Yamamoto
The 58th Spring Meeting2011, The Japan Society of Applied Physics, Mar. 2011, Japanese, Oral presentation
Kanagawa Institute of Technology, Atsugi, [Domestic Conference]

Effects of the insertion of a MgO tunnel barrier on tunneling characteristics in ferromagnet/n-GaAs hetero junction
M. Harada; T. Akiho; K.-i. Matsuda; T. Uemura; M. Yamamoto
46th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2011, Japanese, Oral presentation
Muroran Institute of Technology, Muroran, [Domestic Conference]

Spin-dependent tunneling resistance as a function of MgO barrier thickness in magnetic tunnel junctions withCo2MnSi thin films
S. Hirata; Gui-fang Li; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
46th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2011, Japanese, Oral presentation
Muroran Institute of Technology, Muroran, [Domestic Conference]

Epitaxial growth of Heusler alloy Co2MnSi thin films on MgO-buffered Ge substrate
G. -f. Li; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
4th Int’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Jan. 2011, English
Hokkaido University, Sapporo, Japan, [International presentation]

High tunnel magnetoresistance in fully epitaxial CoFe-buffered Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
H.-x. Liu; T. Taira; K. -i. Matsuda; T. Uemura; M. Yamamoto
4th Int’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Jan. 2011, English
Hokkaido University, Sapporo, Japan, [International presentation]

Effects of MgO tunnel barriers on tunneling anisotropic magnetoresistance in Co2MnSi/n-GaAs junctions
T. Akiho; M. Harada; T. Uemura; K. ?i. Matsuda; M. Yamamoto
The 15th Symposium on the Physics and Application of Spin-Related Phenomena in Semiconductors (PASPS-15), Dec. 2010, Japanese, Oral presentation
University of Tsukuba, Tsukuba, [Domestic Conference]

Highly spin-polarized tunneling characteristics at room temperature in magnetic tunnel junctions with a half-metallic Heusler-alloy spin source and a MgO barrier
H.-x. Liu; T. Taira; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
55th Annual Conf. on Magnetism & Magnetic Materials, Nov. 2010, English
Atlanta, Georgia, USA, [International presentation]

Giant oscillations of spin-dependent tunneling resistances as a function of MgO barrier thickness in fully epitaxial magnetic tunnel junctions of Co2Cr0.6Fe0.4Al/MgO/Co2Cr0.6Fe0.4Al
M. Yamamoto; T. Marukame; T. Ishikawa; T. Taira; K.-i. Matsuda; T. Uemura
55th Annual Conf. on Magnetism & Magnetic Materials, Nov. 2010, English
Atlanta, Georgia, USA,, [International presentation]

Giant tunnel magnetoresistance in half-metallic Co2MnSi-based fully epitaxial magnetic tunnel junctions
T. Taira; H.-x. Liu; S. Hirata; K.-i. Matsuda; T. Uemura; M. Yamamoto
55th Annual Conf. on Magnetism & Magnetic Materials, Nov. 2010, English
Atlanta, Georgia, USA, [International presentation]

Superconducting proximity effect of spin-triplet pairs in NbN/Co2Cr0.6Fe0.4Al/NbN junctions
K.-i. Matsuda; T. Uemura; M. Yamamoto
55th Annual Conf. on Magnetism & Magnetic Materials, Nov. 2010, English
Atlanta, Georgia, USA, [International presentation]

Spin-dependent transport properties in Co2MnSi/MgO/n-GaAs junctions
T. Uemura; M. Harada; T. Akiho; K. ?i. Matsuda; M. Yamamoto
The 34th Annual Conference on MAGNETICS in Japan 2010, Sep. 2010, Japanese, Oral presentation
Tsukuba International Congress Center, Tsukuba, [Domestic Conference]

High tunnel magnetoresistance in fully epitaxial Co50Fe50-buffered Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
H.?x. Liu; T. Taira; Y. Honda; K. -i. Matsuda; T. Uemura; M. Yamamoto
The 34th Annual Conference on MAGNETICS in Japan 2010, Sep. 2010, English, Oral presentation
Tsukuba International Congress Center, Tsukuba, [Domestic Conference]

Differential Conductance Characteristics and their temperature dependences of NbN/Co2Cr0.6Fe0.4Al/NbN junctions
K. ?i. Matsuda; T. Uemura; M. Yamamoto
The 71th Autumn Meeting, The Japan Society of Applied Physics, Sep. 2010, Japanese, Oral presentation
Nagasaki University, Nagasaki, [Domestic Conference]

Giant oscillations in spin-dependent tunneling resistances as a function of barrier thickness in fully epitaxial magnetic tunnel junctions with a MgO barrier
M. Yamamoto; T. Marukame; T. Ishikawa; T. Taira; K.-i. Matsuda; T. Uemura
The 71th Autumn Meeting, The Japan Society of Applied Physics, Sep. 2010, Japanese, Oral presentation
Nagasaki University, Nagasaki, [Domestic Conference]

Spin-dependent transport properties of Co2MnSi/MgO/n-GaAs tunnel junctions
M. Harada; T. Akiho; T. Uemura; K. ?i. Matsuda; M. Yamamoto
The 71th Autumn Meeting, The Japan Society of Applied Physics, Sep. 2010, Japanese, Oral presentation
Nagasaki University, Nagasaki, [Domestic Conference]

High tunnel magnetoresistance of up to 450% at room temperature in epitaxial magnetic tunnel junctions with a Heusler-alloy spin source and a MgO barrier
H.-x. Liu; T. Taira; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 71th Autumn Meeting, The Japan Society of Applied Physics, Sep. 2010, English, Oral presentation
Nagasaki University, Nagasaki, [Domestic Conference]

Tunnel magnetoresistance characteristics of fully epitaxial Co2MnAl/MgO/CoFe MTJs with various Mn compositions in Co2MnAl electrodes
G.-f. Li; T. Taira; S. Hirata; K.-I. Matsuda; T. Uemura; M. Yamamoto
The 2010 Autumn (147th) Meeting of The Japan Institute of Metals, Sep. 2010, English, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Highly spin-polarized tunneling in Heusler-alloy-based magnetic tunnel junctions with a Co2MnSi upper electrode and a MgO barrier
H.-x. Liu; T. Taira; Y. Honda; K.-i. Matsuda; T. Uemura; M. Yamamoto
2010 Int’l Conf. on Solid State Devices and Materials, Sep. 2010, English
Tokyo, Japan, [International presentation]

Electrical detection of a non-local signal in Co2MnSi/MgO/n-GaAs tunnel junctions
M. Harada; T. Uemura; T. Akiho; K.-i. Matsuda; M. Yamamoto
6th Int’l Conf. on the Physics and Application of Spin Related Phenomena in Semiconductors (PASPS-VI), Aug. 2010, English
Tokyo, Japan, [International presentation]

Spin-dependent conductance characteristics of Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions
S. Hirata; T. Taira; T. Ishikawa; K; ?i. Matsuda; T. Uemura; M. Yamamoto
The 57th Spring Meeting, 2010, The Japan Society of Applied Physics, Mar. 2010, Japanese, Oral presentation
Tokai University, Hiratsuka, [Domestic Conference]

Defects induced in nonstoichiometric Co2MnGe thin films investigated through saturation magnetization
G.-f. Li; T. Taira; S. Hirata; Y. Honda; K. ?i. Matsuda; T. Uemura; M. Yamamoto
The 57th Spring Meeting, 2010, The Japan Society of Applied Physics, Mar. 2010, English, Oral presentation
Tokai University, Hiratsuka, [Domestic Conference]

Interfacial-structure dependence of TAMR effect and magnetic crystalline anisotropy in a Co2MnSi/n-GaAs junctions
M. Harada; T. Akiho; K. ?i. Matsuda; T. Uemura; M. Yamamoto
The 57th Spring Meeting, 2010, The Japan Society of Applied Physics, Mar. 2010, Japanese, Oral presentation
Tokai University, Hiratsuka, [Domestic Conference]

Fabrication of Heusler-alloy-based magnetic tunnel junctions having an upper Co2MnSi electrode with various Mn compositions and having a Co50Fe50 lower electrode
H.-x. Liu; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 57th Spring Meeting, 2010, The Japan Society of Applied Physics, Mar. 2010, English, Oral presentation
Tokai University, Hiratsuka, [Domestic Conference]

Influence of film composition on the saturation magnetization of Co2MnGe thin films
G.-f. Li; T. Taira; S. Hirata; Y. Honda; K.?i. Matsuda; T. Uemura; M. Yamamoto
The 2010 Spring (146th) Meetingof The Japan Institute of Metals, Mar. 2010, English, Oral presentation
University of Tsukuba, Tsukuba, [Domestic Conference]

Conductance characteristics of magnetic tunnel junctions with Heusler alloy Co2MnGe thin films fabricated with various film compositions
S. Hirata; T. Taira; K. ?i. Matsuda; T. Uemura; M. Yamamoto
The 2010 Spring (146th) Meetingof The Japan Institute of Metals, Mar. 2010, Japanese, Oral presentation
University of Tsukuba, Tsukuba, [Domestic Conference]

Creation and control of spin current using Heusler alloys
T. Uemura; T. Ishikawa; M. Harada; T. Taira; K. ?i. Matsuda; M. Yamamoto
The 2010 Spring (146th) Meetingof The Japan Institute of Metals, Mar. 2010, Japanese, Keynote oral presentation
University of Tsukuba, Tsukuba, [Invited], [Domestic Conference]

Effect of nonstoichiometry on saturation magnetization of Heusler alloy Co2MnGe thin films
G.-f. Li; T. Taira; S. Hirata; Y. Honda; K. ?i. Matsuda; T. Uemura; M. Yamamoto
45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2010, English, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Fabrication and Transport Properties of NbN/Co2Cr0.6Fe0.4Al/NbN Junctions
S. Imai; T. Ishikawa; K. ?i. Matsuda; T. Uemura; M. Yamamoto
45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2010, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Tunneling anisotropic magnetoresistance effect in a Co2MnSi/n-GaAs Schottky junction
M. Harada; T. Akiho; K. ?i. Matsuda; T. Uemura; M. Yamamoto
45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2010, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Spin-dependent conductance characteristics of Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions fabricated with various film composition
S. Hirata; T. Taira; T. Ishikawa; K.?i. Matsuda; T. Uemura; M. Yamamoto
45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2010, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Fabrication of fully epitaxial NbN/MgO/Co-based Heusler alloy trilayers and their tunnel characteristics
N. Itabashi; T. Taira; K. ?i. Matsuda; T. Uemura; M. Yamamoto
45th Conference of Hokkaido Chapter, The Japan Society of Applied Physics, Jan. 2010, Japanese, Oral presentation
Hokkaido University, Sapporo, [Domestic Conference]

Tunnel magnetoresistance characteristics of Heusler-alloy-based magnetic tunnel junctions having an upper Co2MnSi electrode with various Mn compositions and having a Co50Fe50 lower electrode
H.-x. Liu; T. Ishikawa; K. -i. Matsuda; T. Uemura; M. Yamamoto
The 3rdInt’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Jan. 2010, English
Hokkaido University, Sapporo, Japan, [International presentation]

Effect of nonstoichiometry on saturation magnetization of Heusler alloy Co2MnGe thin film
G.-f. Li; T. Taira; S. Hirata; Y. Honda; K. ?i. Matsuda; T. Uemura; M. Yamamoto
The 3rdInt’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Jan. 2010, English
Hokkaido University, Sapporo, Japan, [International presentation]

Tunneling spectroscopy of Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions
T. Taira; S. Hirata; G.-f. Li; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 3rdInt’l Symposium on Global COE Program of Center for Next-Generation Information Technology Based on Knowledge Discovery and Knowledge Federation, Jan. 2010, English
Hokkaido University, Sapporo, Japan, [International presentation]

Effect of the Mn composition in Co2MnSi electrodes on tunnel magnetoresistance characteristics of Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
T. Ishikawa; H.-x. Liu; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
11th Joint MMM/Intermag Conf., Jan. 2010, English
Washington DC, USA, [International presentation]

Strong bias-voltage dependence of tunneling anisotropic magneto-resistance in epitaxial ferromagnet/n-GaAs junctions
T. Uemura; M. Harada; K.-i. Matsuda; M. Yamamoto
11th Joint MMM/Intermag Conf., Jan. 2010, English
Washington DC, USA, [International presentation]

Spin-dependent tunneling characteristics of Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions
T. Taira; S. Hirata; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
11th Joint MMM/Intermag Conf., Jan. 2010, English
Washington DC, USA, [International presentation]

Fabrication and Transport Properties of NbN/Co2Cr0.6Fe0.4Al/NbN Lateral Junctions
S. Imai; K.-i. Matsuda; T. Ishikawa; T. Uemura; M. Yamamoto
9th Int’l Conf. on Materials and Mechanisms of Superconductivity (M2S-IX), Sep. 2009, English
Shinjuku, Tokyo, Japan, [International presentation]

Tunneling anisotropic magneto-resistance in an epitaxial Co2MnSi/n-GaAs junction
M. Harada; T. Uemura; Y. Imai; K.-i. Matsuda; M. Yamamoto
The 14th Int’l Conf. on Modulated Semiconductor Structures (MSS-14), Jul. 2009, English
Kobe, Japan, [International presentation]

Spin-dependent tunneling characteristics of fully epitaxial Co2MnGe/MgO/Co2MnGe magnetic tunnel junctions
T. Taira; S. Hirata; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
20th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS2009), Jul. 2009, English
Berlin, Germany, [International presentation]

Tunneling spectroscopy of magnetic tunnel junctions with Heusler alloy Co2MnGe electrodes and a MgO barrier
S. Hirata; T. Taira; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2009), Jul. 2009, English
Karlsruhe, Germany, [International presentation]

Spin-dependent electronic structure of Heusler alloy Co2MnSi upper electrodes in magnetic tunnel junctions
T. Ishikawa; N. Itabashi; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2009), Jul. 2009, English
Karlsruhe, Germany, [International presentation]

Transport properties of a junction consisting of two NbN electrodes coupled by a Co-based Heusler alloy Co2Cr0.6Fe0.4Al channel
K.-i. Matsuda; S. Imai; T. Ishikawa; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2009), Jul. 2009, English
Karlsruhe, Germany, [International presentation]

Spin-dependent tunneling in half-metallic Heusler alloy-based magnetic tunnel junctions with a MgO barrier
M. Yamamoto; T. Ishikawa; T. Taira; T. Marukame; K.-i. Matsuda; T. Uemura
Int’l Conf. on Magnetism (ICM2009), Jul. 2009, English
Karlsruhe, Germany, [International presentation]

Simulation of tunneling magnetoresistance used to detect domain-wall structure and motion in a ferromagnetic wire
K. Sawada; T. Uemura; M. Masuda; K.-i. Matsuda; M. Yamamoto
IEEE Int’l Magnetics Conf. 2009, May 2009, English
Sacramento, CA, USA, [International presentation]

Tunneling Anisotropic Magneto-resistance in an Epitaxial CoFe/n-GaAs Junction
T. Uemura; Y. Imai; M. Harada; K.-i. Matsuda; M. Yamamoto
IEEE Int’l Magnetics Conf. 2009, May 2009, English
Sacramento, CA, USA, [International presentation]

Tunnel magnetoresistance characteristics of post-deposition-annealed Co2MnGe/MgO/CoFe tunnel junctions
T. Taira; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
2008 Material Research Society (MRS) Fall Meeting, Dec. 2008, English
Boston, MA, USA, [International presentation]

Spin-polarized tunneling in fully epitaxial magnetic tunnel junctions with Heusler alloy thin films and a MgO barrier
M. Yamamoto; T. Ishikawa; K.-i. Matsuda; T. Uemura
2008 Material Research Society (MRS) Fall Meeting, Dec. 2008, English
Boston, MA, USA, [International presentation]

Tunneling conductance characteristics for Co2Cr0.6Fe0.4Al/MgO/Co2Cr0.6Fe0.4Al magnetic tunnel junctions
N. Itabashi; T. Ishikawa; K. Yonemura; K.-i. Matsuda; T. Uemura; M. Yamamoto
2008 Material Research Society (MRS) Fall Meeting, Dec. 2008, English
Boston, MA, USA, [International presentation]

Tunneling spectroscopy of fully epitaxial Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
T. Ishikawa; N. Itabashi; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
2008 Material Research Society (MRS) Fall Meeting, Dec. 2008, English
Boston, MA, USA, [International presentation]

Half-metallic electronic structure of Co2MnSi electrodes proved by tunneling spectroscopy
T. Ishikawa; N. Itabashi; T. Taira; K.-i. Matsuda; T. Uemura; M. Yamamoto
53rd Magnetism and Magnetic Materials Conf., Nov. 2008, English
Austin, TX, USA, [International presentation]

Spin-dependent tunneling characteristics of Co2MnGe/MgO/CoFe tunnel junctions
T. Taira; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
53rd Magnetism and Magnetic Materials Conf., Nov. 2008, English
Austin, TX, USA, [International presentation]

Tunneling spectroscopy of Co2Cr0.6Fe0.4Al/MgO/CoFe magnetic tunnel junctions
K. Yonemura; T. Ishikawa; N. Itabashi; K.-i. Matsuda; T. Uemura; M. Yamamoto
53rd Magnetism and Magnetic Materials Conf., Nov. 2008, English
Austin, TX, USA, [International presentation]

Spin-dependent electronic structures of Co2Cr0.6Fe0.4Al electrodes investigated through tunneling spectroscopy
N. Itabashi; T. Ishikawa; K. Yonemura; K.-i. Matsuda; T. Uemura; M. Yamamoto
53rd Magnetism and Magnetic Materials Conf., Nov. 2008, English
Austin, TX, USA, [International presentation]

Transport Properties of Nb/PdNi bilayers and Nb/PdNi/Nb Josephson junctions
K.-i. Matsuda; Y. Akimoto; T. Uemura; M. Yamamoto
25th Int’l Conf. on Low Temp. Physics, Aug. 2008, English
Amsterdam, The Netherlands, [International presentation]

Spin-dependent tunneling spectroscopy of fully epitaxial magnetic tunnel junctions with Heusler alloy Co2Cr0:6Fe0:4Al electrodes and a MgO barrier
N. Itabashi; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
25th Int’l Conf. on Low Temp. Physics, Aug. 2008, English
Amsterdam, The Netherlands, [International presentation]

Fabrication and characterization of magnetic tunnel junction field sensors with a Co2MnSi thin film
M. Masuda; T. Uemura; K.-i. Matsuda; M. Yamamoto
IEEE Int'l Magnetics Conf. Europe 2008, May 2008, English
Madrid, Spain, [International presentation]

Spin-dependent tunneling conductance in fully epitaxial Co2MnSi/MgO/Co2MnsI tunnel junctions
T. Ishikawa; N. Itabashi; K. Matsuda; T. Uemura; M. Yamamoto
IEEE Int'l Magnetics Conf. Europe 2008, May 2008, English
Madrid, Spain, [International presentation]

Heusler alloy-based fully epitaxial magnetic tunnel junctions with a MgO barrier
M. Yamamoto; T. Uemura; K.-i. Matsuda
2008 RCIQE Int’l Seminar on “Advanced Semiconductor Materials and Devices”, Mar. 2008, English, Keynote oral presentation
Sapporo, Japan, [Invited], [International presentation]

Magnetic and transport properties of superconductor/ferromagnet bilayer microbridges
K.-i. Matsuda; Y. Akimoto; T. Uemura; M. Yamamoto
52nd Magnetism and Magnetic Materials Conf., Nov. 2007, English
Tampa, Florida, USA, [International presentation]

Electrical characterization of epitaxial Co2MnSi/MgO/n-GaAs tunnel junctions
S. Kawagishi; T. Uemura; Y. Imai; K.-i. Matsuda; M. Yamamoto
52nd Magnetism and Magnetic Materials Conf., Nov. 2007, English
Tampa, Florida, USA, [International presentation]

Electronic and magnetic properties of Heusler alloy Co2MnSi epitaxial ultrathin films facing a MgO barrier investigated by X-ray magnetic circular dichroism
T. Saito; T. Katayama; A. Emura; N. Sumida; N. Matsuoka; T. Ishikawa; T. Uemura; M. Yamamoto; D. Asakura; T. Koide
52nd Magnetism and Magnetic Materials Conf., Nov. 2007, English
Tampa, Florida, USA, [International presentation]

Spin-dependent tunneling in fully epitaxial Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
T. Ishikawa; S. Hakamata; K.-i. Matsuda; T. Uemura; M. Yamamoto
52nd Magnetism and Magnetic Materials Conf., Nov. 2007, English
Tampa, Florida, USA, [International presentation]

Oscillations in tunneling resistance as a function of MgO barrier thickness in fully epitaxial magnetic tunnel junctions of Co2Cr0.6Fe0.4Al/MgO/Co50Fe50
M. Yamamoto; T. Marukame; T. Ishikawa; K. Matsuda; T. Uemura
52nd Magnetism and Magnetic Materials Conf., Nov. 2007, English
Tampa, Florida, USA, [International presentation]

Highly spin-polarized tunneling in Heusler alloy-based fully epitaxial magnetic tunnel junctions with a MgO tunnel barrier
M. Yamamoto; T. Marukame; T. Ishikawa; K. Matsuda; T. Uemura
52nd Magnetism and Magnetic Materials Conf., Nov. 2007, English
Tampa, Florida, USA, [International presentation]

Epitaxial growth and characterization of Co2MnSi thin films on GaAs with MgO interlayer
T. Uemura; T. Yano; Y. Imai; K. Matsuda; M. Yamamoto
The 13th Int’l Conf. on Modulated Semiconductor Structures (MSS13), Jul. 2007, English
Genova, Italy, [International presentation]

Four-state Magnetic Random Access Memory and Ternary Content Addressable Memory using CoFe-based Magnetic Tunnel Junctions
T. Uemura; T. Marukame; K.-i. Matsuda; M. Yamamoto
37th Int’l Symposium on Multiple-Valued Logic, May 2007, English
Oslo, Norway, [International presentation]

Magnetic and transport properties of Nb/Pd0.85Ni0.15 bilayer structures
H. Niwa; K. Matsuda; Y. Akimoto; T. Uemura; M. Yamamoto
The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Mar. 2007, English
Sapporo, Japan, [International presentation]

Epitaxial growth and characterization of Co2Cr0.6Fe0.4Al thin films on GaAs with MgO interlayer
T. Yano; T. Uemura; K. Matsuda; M. Yamamoto
The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Mar. 2007, English
Japan, [International presentation]

Fabrication of magnetic tunnel junction field sensors using a Co2MnSi thin film
S. Yasuda; M; Masuda; T. Uemura; M. Yamamoto
The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Mar. 2007, English
Sapporo, Japan, [International presentation]

Improved tunnel magnetoresistance characteristics of magnetic tunnel junctions with a Heusler alloy Co2MnGe thin film
S. Hakamata; T. Ishikawa; T. Marukame; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Mar. 2007, English
Sapporo, Japan, [International presentation]

Spin-dependent tunneling in fully epitaxial Co2MnSi/MgO/Co50Fe50 magnetic tunnel junctions
T. Ishikawa; T. Marukame; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Mar. 2007, English
Sapporo, Japan, [International presentation]

High tunnel magnetoresistance in fully epitaxial Co2Cr0.6Fe0.4Al/MgO/Co50Fe50 magnetic tunnel junctions with exchange biasing
T. Marukame; T. Ishikawa; S. Hakamata; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 4th Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Mar. 2007, English
Sapporo, Japan, [International presentation]

Spin-polarized tunneling in fully epitaxial magnetic tunnel junctions with a full-Heusler alloy thin film
M. Yamamoto; T. Uemura; K.-i. Matsuda
The 4th Int’l Symposium on Ubiquitous Knowledge Network Environment, Mar. 2007, English, Keynote oral presentation
Sapporo, Japan, [Invited], [International presentation]

Spin-dependent tunneling in fully epitaxial magnetic tunnel junctions with a Heusler alloy thin film and a MgO barrier
M. Yamamoto; T. Uemura; K.-i. Matsuda
The 2nd RIEC Int’l Workshop on Spintronics?MgO-based Magnetic Tunnel Junctions?, Feb. 2007, English, Keynote oral presentation
Sendai, Japan, [Invited], [International presentation]

Dependence of magnetoresistance characteristics of magnetic tunnel junctions with a Heusler alloy thin film of either Co2MnGe or Co2MnSi on film composition
S. Hakamata; T. Ishikawa; T. Marukame; K. Matsuda; T. Uemura; M. Arita; M. Yamamoto
10th Joint MMM/Intermag Conf., Jan. 2007, English
Baltimore, USA, [International presentation]

Fabrication of fully epitaxial Co2Cr0.6Fe0.4Al/MgO/Co2Cr0.6Fe0.4Al
T. Marukame; T. Ishikawa; S. Hakamata; K. Matsuda; T. Uemura; M. Yamamoto
10th Joint MMM/Intermag Conf., Jan. 2007, English
Baltimore, USA, [International presentation]

Four-state magnetoresistance in epitaxial CoFe-based magnetic tunnel junction
T. Uemura; T. Marukame; K. Matsuda; M. Yamamoto
10th Joint MMM/Intermag Conf., Jan. 2007, English
Baltimore, USA, [International presentation]

Magnetic and Transport Properties of Nb/PdNi Bilayers
K.-i. Matsuda; H. Niwa; Y. Akimoto; T. Uemura; M. Yamamoto
IEEE Int’l Conf. on Appl. Supercond., Aug. 2006, English
Seatle, USA, [International presentation]

Fabrication of exchange-biased epitaxial magnetic tunnel junctions with a Co-based full-Heusler alloy thin film
T. Ishikawa; S. Hakamata; T. Marukame; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2006), Aug. 2006, English
Kyoto, Japan, [International presentation]

Analysis of magnetic anisotropy for Co2Cr0.6Fe0.4Al thin films epitaxially grown on GaAs
T. Uemura; T. Yano; K.-i. Matsuda; M. Yamamoto
Int’l Conf. on Magnetism (ICM2006), Aug. 2006, English
Kyoto, Japan, [International presentation]

Spin-dependent transport properties of fully epitaxial Co2MnSi/MgO/CoFe tunnel junctions
T. Marukame; H. Kijima; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2006), Aug. 2006, English
Kyoto, Japan, [International presentation]

Fabrication of fully epitaxial magnetic tunnel junctions using Co2MnSi thin film and MgO tunnel barrier
H. Kijima; T. Ishikawa; T. Marukame; K. -i. Matsuda; T. Uemura; M. Yamamoto
Int’l Conf. on Magnetism (ICM2006), Aug. 2006, English
Kyoto, Japan, [International presentation]

Epitaxial growth of Co-based full-Heusler alloy thin films of Co2Cr0.6Fe0.4Al, Co2MnGe and Co2MnSi on MgO-buffered MgO substrate
T. Ishikawa; T. Marukame; H. Kijima; K.-i. Matsuda; T. Uemura; M. Yamamoto
19th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS 2006), Aug. 2006, English
Sendai, Japan, [International presentation]

MgO barrier thickness dependence of tunnel magnetoresistance in fully epitaxial magnetic tunnel junctions with Co2Cr0.6Fe0.4Al thin film
T. Marukame; T. Ishikawa; H. Kijima; K.?i. Matsuda; T. Uemura; M. Yamamoto
19th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS 2006), Aug. 2006, English
Sendai, Japan, [International presentation]

Spin-dependent conductance versus voltage characteristics of fully epitaxial magnetic tunnel junctions with a Co-based full-Heusler alloy thin film and a MgO barrier
M. Yamamoto; T. Marukame; K.?i. Matsuda; T. Uemura
19th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS 2006), Aug. 2006, English
Sendai, Japan, [International presentation]

Tunnel magnetoresistance in fully epitaxial Co2MnSi/MgO/Co50Fe50 magnetic tunnel junctions
H. Kijima; T. Ishikawa; T. Marukame; K.?i. Matsuda; T. Uemura; M. Yamamoto
19th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS 2006), Aug. 2006, English
Sendai, Japan, [International presentation]

Structural and magnetic properties of Co2Cr0.6Fe0.4Al thin films epitaxially grown on GaAs with and without MgO interlayer
T. Uemura; T. Yano; K.?i. Matsuda; M. Yamamoto
19th Int’l Colloquium on Magnetic Films and Surfaces (ICMFS 2006), Aug. 2006, English
Sendai, Japan, [International presentation]

Design and analysis of magnetic random access memory consisting of magnetic tunnel junction and tunnel diode
T. Uemura; M. Yamamoto
15th Int’l Workshop on Post-Binary ULSI Systems, May 2006, English
Singapore, [International presentation]

Highly spin-polarized tunneling in fully epitaxial magnetic tunnel junctions using full-Heusler alloy Co2Cr0.6Fe0.4Al thin film and MgO tunnel barrier
T. Marukame; T. Ishikawa; H. Kijima; W. Sekine; K.?i. Matsuda; T. Uemura; M. Yamamoto
IEEE Int'l Magnetics Conf. 2006, May 2006, English
San Diego, CA, USA, [International presentation]

Exchange bias effect on full-Heusler alloy Co2Cr0.6Fe0.4Al epitaxial thin films
T. Ishikawa; T. Marukame; H. Niwa; K.?i. Matsuda; T. Uemura; M. Yamamoto
IEEE Int'l Magnetics Conf. 2006, May 2006, English
San Diego, CA, USA, [International presentation]

Epitaxial growth of full-Heusler alloy Co2MnSi thin films on MgO-buffered MgO substrates
H. Kijima; T. Ishikawa; T. Marukame; H. Koyama; K; ?i. Matsuda; T. Uemura; M. Yamamoto
IEEE Int'l Magnetics Conf. 2006, May 2006, English
San Diego, CA, USA, [International presentation]

Fabrication of microfluidic channel integrated with MOSFET
S. Yasuda; T. Uemura; K. -i. Matsuda; M. Yamamoto
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Feb. 2006, English
Sapporo, Japan, [International presentation]

Magnetic and Structural Properties of Pd1-xNix Thin Films for Superconductor / Ferromagnet / Superconductor p-Josephson junction devices
H. Niwa; K.-i. Matsuda; Y. Akimoto; T. Uemura; M. Yamamoto
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Feb. 2006, English
Sapporo, Japan, [International presentation]

Anisotropic tunnel magneto-resistance in (Ga,Mn)As/AlAs/(Ga,Mn)As magnetic tunnel junctions
T. Sone; T. Uemura; K. ?i. Matsuda; M. Yamamoto
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Feb. 2006, English
Sapporo, Japan, [International presentation]

Epitaxial growth of Co2Cr0.6Fe0.4Al thin films on GaAs substrate by magnetron sputtering
T. Yano; T. Uemura; K. ?i. Matsuda; M. Yamamoto
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Feb. 2006, English
Sapporo, Japan, [International presentation]

Dependence of tunnel magnetoresistance on MgO tunnel barrier thickness in epitaxial magnetic tunnel junctions using Heusler alloy thin film
W. Sekine; T. Marukame; K. ?i. Matsuda; T. Uemura; M. Yamamoto
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Feb. 2006, English
Sapporo, Japan, [International presentation]

Fabrication of fully epitaxial magnetic tunnel junctions using full-Heusler alloy Co2MnSi thin film
H. Koyama; H. Kijima; K. ?i. Matsuda; T. Uemura; M. Yamamoto
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Feb. 2006, English
Sapporo, Japan, [International presentation]

Epitaxial growth of full-Heusler alloy Co2MnSi thin films on MgO substrates by magnetron sputtering
H. Kijima; H. Koyama; K. ?i. Matsuda; T. Uemura; M. Yamamoto
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Feb. 2006, English
Sapporo, Japan, [International presentation]

Epitaxial growth and characterization of full-Heusler alloy Co2MnGe thin films
T. Ishikawa; T. Marukame; K. ?i. Matsuda; T. Uemura; M. Yamamoto
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Feb. 2006, English
Sapporo, Japan, [International presentation]

Tunnel magnetoresistance characteristics of fully epitaxial magnetic tunnel junctions using Co2MnGe thin film
T. Marukame; T. Ishikawa; K.-i. Matsuda; T. Uemura; M. Yamamoto
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Quantum Nanoelectronics Workshop, Feb. 2006, English
Sapporo, Japan, [International presentation]

Epitaxially grown full-Heusler alloy thin films and application to magnetic tunnel junctions
M. Yamamoto; T. Uemura; K.-i. Matsuda
The 3rd Int’l Symp. on Ubiquitous Knowledge Network Environment, Feb. 2006, English, Keynote oral presentation
Sapporo, Japan, [Invited], [International presentation]

Effect of ferromagnetic-layer thickness on the critical current in Nb/Pd1-xNix/Nb Josehpson p-junctions
K. -i. Matsuda; H. Niwa; Y. Akimoto; T. Uemura; M. Yamamoto
2006 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (IV)”, Feb. 2006, English
Sapporo, Japan, [International presentation]

Characterization of anisotropic tunnel magneto-resistance in (Ga,Mn)As/AlAs/(Ga,Mn)As magnetic tunnel junctions
T. Uemura; T. Sone; K; ?i. Matsuda; M. Yamamoto
2006 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (IV)”, Feb. 2006, English
Sapporo, Japan, [International presentation]

Epitaxially grown Co2MnGe thin films and application to fully epitaxial magnetic tunnel junctions
T. Marukame; T. Ishikawa; K. -i. Matsuda; T. Uemura; M. Yamamoto
2006 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (IV)”, Feb. 2006, English
Sapporo, Japan, [International presentation]

Structural and magnetic properties of epitaxially grown full-Heusler alloy Co2MnGe thin films deposited using magnetron sputtering
T. Ishikawa; T. Marukame; K. ?i. Matsuda; T. Uemura; M. Yamamoto
50th Annual Conf. on Magnetism & Magnetic Materials, Oct. 2005, English
San Jose, CA, USA, [International presentation]

Tunnel magnetoresistance in epitaxial magnetic tunnel junctions using full-Heusler alloy Co2MnGe thin film and MgO tunnel barrier
T. Marukame; T. Ishikawa; K. ?i. Matsuda; T. Uemura; M. Yamamoto
50th Annual Conf. on Magnetism & Magnetic Materials, Oct. 2005, English
San Jose, CA, USA, [International presentation]

Analysis of anisotropic tunnel magneto-resistance of GaMnAs/AlAs/GaMnAs magnetic tunnel junction
T. Uemura; R. Miura; T. Sone; K. Matsuda; M. Yamamoto
12th Int’l Conf. on Modulated Semiconductors (MSS 12), Jul. 2005, English
Alburquerque, New Mexico, USA, [International presentation]

High Tunnel Magnetoresistance in Epitaxial Co2Cr0.6Fe0.4Al/MgO/CoFe Tunnel Junctions
T. Marukame; T. Kasahara; K. Matsuda; T. Uemura; M. Yamamoto
IEEE Int’l Magnetics Conf., Apr. 2005, English
Nagoya, Japan, [International presentation]

Epitaxial growth and characterization of full-Huesler alloy Co2Cr0.6Fe0.4Al thin films for magnetic tunnel junctions
T. Marukame; T. kasahara; K. Matsuda; T. Uemura; M. Yamamoto
2nd Int. Workshop on Ubiquitous Knowledge Network Environment, Mar. 2005, English
Sapporo, Japan, [International presentation]

Fully epitaxial magnetic tunnel junctions using full-Heusler alloy thin film
M. Yamamoto; T. Uemura; K. Matsuda
2nd Int. Workshop on Ubiquitous Knowledge Network Environment, Mar. 2005, English, Keynote oral presentation
Sapporo, Japan, [Invited], [International presentation]

Fabrication of fully epitaxial magnetic tunnel junctions using full-Heusler alloy Co2Cr0.6Fe0.4Al
T. Marukame; T. Kasahara; K. Matsuda; T. Uemura; M. Yamamoto
2005 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (III)”, Feb. 2005, English
Sapporo, Japan, [International presentation]

T. Uemura, K. Sekine, K. Matsuda and M. Yamamoto
T. Uemura; K. Sekine; K. Matsuda; M. Yamamoto
49th Annual Conf. on Magnetism and Magnetic Materials, Nov. 2004, English
Jacksonville, Florida, USA, [International presentation]

Epitaxial growth of Fe/MgO/Fe heterostructures on SrTiO3 substrates by magnetron sputtering
T. Marukame; K.-i. Matsuda; T. Uemura; M. Yamamoto
49th Annual Conf. on Magnetism and Magnetic Materials, Nov. 2004, English
Jacksonville, Florida, USA, [International presentation]

Magnetic and Electrical Properties of (La, Sr)MnO3 Sputtered on SrTiO3-buffered Si Substrate
T. Uemura; Y. Takagi; K. Sekine; K. Matsuda; M. Yamamoto
2004 Int’l Conf. on Solid State Devices and Materials, Sep. 2004, English
Tokyo, Japan, [International presentation]

Multilevel Magnetic Random Access Memory Consisting of Magnetic Tunnel Junction and Resonant Tunnel Diode
T. Uemura; M. Yamamoto
“Satellite Session on Quantum Nano Electronics for Meme-Media-Based Information Technologies”, 7th Hokkaido University-Seoul National University Joint Symposium, Jul. 2004, English
Sapporo, Japan, [International presentation]

Epitaxial growth of Fe/MgO/Fe heterostructures by magnetron sputtering
T. Marukame; M. Yamamoto; T. Uemura; K. Matsuda
“Satellite Session on Quantum Nano Electronics for Meme-Media-Based Information Technologies”, 7th Hokkaido University-Seoul National University Joint Symposium, Jul. 2004, English
Sapporo, Japan, [International presentation]

Epitaxial growth of Co2Cr0.6Fe0.4Al Heusler alloy films on MgO (001) substrate
K. Matsuda; T. Kasahara; T. Marukame; T. Uemura; M. Yamamoto
“Satellite Session on Quantum Nano Electronics for Meme-Media-Based Information Technologies”, 7th Hokkaido University-Seoul National University Joint Symposium, Jul. 2004, English
Sapporo, Japan, [International presentation]

Characterization of (La, Sr)MnO3-d Films Deposited by Magnetron Sputtering on Si Substrate
T. Uemura; K. Sekine; K. Matsuda; M. Yamamoto
2004 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (II)”, Feb. 2004, English
Sapporo, Japan, [International presentation]

Demonstration of Functional Magnetic Tunnel Junction with Negative Differential Resistance
T. Uemura; S. Honma; T. Marukame; M. Yamamoto
2004 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (II)”, Feb. 2004, English
Sapporo, Japan, [International presentation]

Preparation and characterization of Co2Cr0.6Fe0.4Al Heusler alloy thin films grown on MgO substrate by magnetron sputtering
T. Kasahara; K. Matsuda; T. Marukame; T. Uemura; M. Yamamoto
2004 RCIQE Int. Seminar for 21st Century COE Program: “Quantum Nanoelectronics for Meme-Media-Based Information Technologies (II)”, Feb. 2004, English
Sapporo, Japan, [International presentation]

Proposal and Experimental Demonstration of Novel MRAM Cell Using Magnetic Tunnel Junction in Combination with Negative Differential Resistance Device
M. Yamamoto; T. Uemura
1st Int. Workshop on Ubiquitous Knowledge Network Environment, Nov. 2003, English, Keynote oral presentation
Sapporo, Japan, [Invited], [International presentation]

Demonstration of Enhanced Tunneling Magneto Resistance Ratio for a Magnetic Tunnel Junction Connected in Parallel with a Tunnel Diode
T. Uemura; S. Honma; T. Marukame; M. Yamamoto
2003 Int’l Conf. on Solid State Devices and Materials, Sep. 2003, English
Tokyo, Japan, [International presentation]

Observation of Large Room-temperature Negative Differential Resistance in GaAsNSe/GaAs and GaAsNSb/GaAs Superlattices Grown on (001) GaAs
K. Uesugi; M. Kurimoto; I. Suemune; M. Yamamoto; T. Uemura; H. Machida; N. Shimoyama
The 11th Int’l. Conf. on Modulated Semiconductor Structures (MSS11), Jul. 2003, English
Nara, Japan, [International presentation]

Proposal of Four-Valued MRAM based on MTJ/RTD Structure
T. Uemura; M. Yamamoto
33rd Int’l Symp. on Multiple-Valued Logic, May 2003, English
Tokyo, Japan, [International presentation]

Proposal and Analysis of a Ferromagnetic Triple-Barrier Resonant-Tunneling Spin Filter
T. Uemura; T. Marukame; M. Yamamoto
Int’l Magnetics Conf. (INTERMAG2003), Apr. 2003, English
Boston, Massachusetts, U.S.A., [International presentation]

Analysis of a Triple Barrier Structure Consisting of Ferromagnetic and Non-magnetic Quantum Wells
T. Marukame; T. Uemura; M. Yamamoto
2003 RCIQE Int. Seminar on “Quantum Nanoelectronics for Meme-Media-Based Information Technologies”, Feb. 2003, English
Sapporo, Japan, [International presentation]

■ Syllabus

電子デバイス学特論, 2024年, 修士課程, 情報科学院

電子デバイス学特論, 2024年, 博士後期課程, 情報科学研究科

電子デバイス学特論, 2024年, 博士後期課程, 情報科学院

ディジタル回路, 2024年, 学士課程, 工学部

応用数学演習Ⅱ, 2024年, 学士課程, 工学部

電気電子工学演習Ⅲ, 2024年, 学士課程, 工学部

■ Affiliated academic society

IEEE

THE MAGNETICS SOCIETY OF JAPAN

THE JAPAN SOCIETY OF APPLIED PHYSICS

■ Research Themes

磁性ワイル半金属磁気トンネル接合
科学研究費助成事業挑戦的研究(萌芽)
Jun. 2022 - Mar. 2025
山ノ内路彦; 植村哲也
日本学術振興会, 挑戦的研究(萌芽), 北海道大学, Coinvestigator, 22K18961

ワイル半金属を用いた電流誘起スピン軌道トルクの解明とそのデバイス応用
科学研究費助成事業基盤研究(B)
Apr. 2020 - Mar. 2023
植村哲也; 近藤憲治
本研究の目的は，磁性ワイル半金属材料において発現する強いスピン軌道相互作用を利用した強磁性体磁化制御の学理を確立し，高速性・低消費電力性に優れたスピントロニクスデバイスを実現することである．そのため，ワイル半金属であることが理論的に指摘されているホイスラー合金（以下，ワイル型ホイスラー合金とよぶ）をスピン源としたスピン軌道トルク(SOT)の特性を理論および実験により明らかにするとともに，これを利用した強磁性体磁化制御を確立する．
2020年度は主に，ワイル型ホイスラー合金の探索とその異常ホール効果を活用した強磁性体の磁化制御に取り組んだ．具体的には，フェルミ準位近傍にワイル点があることが理論的に示され，また実験的にも大きな異常ホール効果が観測されているCo2MnAlやCo2MnGaのホイスラー合金薄膜に着目し，それらの結晶構造解析，及び異常ホール効果や縦磁気抵抗効果などの磁気輸送特性評価を通じて，薄膜の成膜条件を最適化した．さらにこれらをスピン源として，MnGa/Co2MnSi強磁性体二層膜のSOT磁化反転を実証した．
また，磁性ワイル半金属の磁気伝導率を理論的に検討した．有効モデルとして，Type-IとType-IIの両方のタイプを表現できる有効ハミルトニアンを使用し，このモデルの磁気伝導率をBerry曲率が考慮された古典ボルツマン方程式によって計算したところ，Type-Iのワイル半金属では従来から知られた，カイラルアノマリによる負の磁気抵抗効果が得られたが，Type-IIのワイル半金属では，カイラルアノマリによる負の磁気抵抗効果のみならず，正の磁気抵抗効果がカイラルアノマリによっておこることが分かった．これは，Type-IIでは磁場印可によって形成されるランダウ準位の曲率が変わらず，Type-Iではランダウ準位の曲率が反転することが原因であることを見出した．
日本学術振興会, 基盤研究(B), 北海道大学, Principal investigator, 20H02174

Spin-orbit-torque induced magnetization switching for halfmetallic ferromagnet
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
Apr. 2017 - Mar. 2020
Uemura Tetsuya
The purpose of this study is to clarify the physics of spin orbit torque produced in a heterostructure consisting of a non-magnetic material with strong spin orbit interaction and a 100% spin-polarized half-metallic material, and to develop a basic technology to realize a novel magnetoresistance device and/or self-excited oscillator with high performance. To do this, a novel three-terminal magnetic tunnel junction consisting of a non-magnetic material with a strong spin orbit interaction and a half-metallic Co-based Heusler alloy electrodes was fabricated, and clear SOT-induced magnetization switching for the Co-based Heusler alloy was demonstrated.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Principal investigator, 17H03225

A study of both materials and phenomena with strong spin-orbit-interaction based on topology concept and an application of them to spintronics devices
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
Oct. 2016 - Mar. 2019
Kondo Kenji
Many researchers have investigated quantum spin Hall effects（QSH） in honeycomb-materials like graphenes. However, they performed a calculation of electronic structures of QSH phase under the open boundary conditions, assuming that the shapes at the open boundaries (edges) are zigzag-type. This is because there exists a small gap at Fermi-level when you examine electronics structures of QSH phase of nanoribbons with armchair-type edges in detail. This fact suggests that the bulk-edge correspondence seems to be broken.
Generally, the QSH phase in bulk materials matches the QSH phase in nanoribbons according to the bulk-edge correspondence. However, we have found that the QSH phase in nanoribbons does not match the QSH phase in bulk materials with decreasing the widths.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Coinvestigator, 16K04872

Development of all-electrical control of nuclear spin states using nuclear electric resonance
Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
Apr. 2015 - Mar. 2017
Uemura Tetsuya
Nuclear spins in semiconductors are an ideal system for implementing quantum bits (qubits) for quantum computation because they have an extremely long coherence time. In this project, an all-electrical control of nuclear spin states has been developed by the combined use of an electrical spin injection from a highly polarized spin source into a semiconductor and the nuclear electric resonance (NER). An efficient spin injection into GaAs from a half-metallic spin source of Co2MnSi and an efficient gate control of spin-injection signals were demonstrated. Moreover, an efficient nuclear polarization through the interactions between electron spins and nuclear spins and the electrical control through NER induced by an RF electric field applied to the gate were demonstrated. This provides a novel all-electrical solid-state NER system with high spatial resolution and high sensitivity needed to implement scalable nuclear-spin based qubits.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, Principal investigator, 15K13960

Coherent control of nuclear spin using spin injection into semiconductor for application to quntum information devices
Grants-in-Aid for Scientific Research
2013 - 2015
UEMURA TETSUYA
Nuclear spins in semiconductors are an ideal system for implementing quantum bits (qubits) for quantum computation because they have an extremely long coherence time. In this project, a novel nuclear magnetic resonance (NMR) system that uses spin injection from a highly polarized spin source has been developed. An efficient spin injection into GaAs from a half-metallic spin source of Co2MnSi enabled an efficient dynamic nuclear polarization of Ga and As nuclei in GaAs and a sensitive detection of NMR signals. Moreover, coherent control of nuclear spins, or the Rabi oscillation between two quantum levels formed at Ga nuclei, induced by a pulsed NMR has been demonstrated at a relatively low magnetic field of approximately 0.1 T. This provides a novel all-electrical solid-state NMR system with the high spatial resolution and high sensitivity needed to implement scalable nuclear-spin based qubits.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Principal investigator, Competitive research funding, 25286039

ハーフメタルと高移動度半導体の高品質ヘテロ構造の製作と半導体スピン輸送特性の研究
科学研究費助成事業基盤研究(A)
May 2011 - Mar. 2014
山本眞史; 植村哲也; 松田健一
本研究の目的は本質的に大きなスピン偏極率を有するハーフメタル材料のCo基ホイスラー合金と，高移動度半導体チャネル(Ge等)を融合する高品質エピタキシャルヘテロ構造の実現を通して，次世代半導体スピントロニクスの基盤を構築することである．平成24年度は，強磁性CoFe電極からMgOバリアを通したn-Geチャネルへのスピン注入の特性を実験的に詳細に検討し，以下の知見を明らかにした．
CoFe/MgO/n-Ge接合に対して，2.25 nmから2.75 nm の範囲のMgOバリア厚み(t_MgO)に対して，室温で，3端子配置により明瞭なHanle信号(磁化は面内，磁場を面に垂直に印加)および逆Hanle信号(磁場を面内に印加)を観測した(スピン注入の方向: 強磁性体から半導体チャネルへのスピン注入)．また，スピン信号ΔVの大きさ(Hanle信号と逆Hanle信号の和)から見積もったspin-RA積(ΔRsA=(ΔV/I_bias)A)は，例えばt_MgO=2.4 nmの接合に対して，半導体へのスピン注入の標準理論(Fert and Jaffres, 2001)の値の4桁大きな値であった．さらに，spin-RA積はt_MgOに対して指数関数的な依存性を示すことを見出した．一方，標準理論では，spin-RA積はt_MgOに対して依存性を示さない．このように，これらの実験結果は，観測されたHanle信号が半導体Geチャネルでのスピン蓄積によるというモデルでは説明できない．この結果を説明するため，トンネル接合界面に存在する局在状態での，磁場によるスピンの歳差運動によりスピン偏極率が低下し，このためフェルミレベルでのアップスピンとダウンスピンの波数が変化し，結果として，トンネル確率が磁場によって変調されるというモデルを提案した．
日本学術振興会, 基盤研究(A), 北海道大学, Coinvestigator, 23246055

Highly-efficient spin-polarized current source using half-metallic ferromagnet/superconductor junctions.
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
2010 - 2012
MATSUDA Ken-ichi; YAMAMOTO Masafumi; UEMURA Tetsuya
In this study, epitaxial growth of Co-based Heusler alloy/superconductor hetero-structures were achieved. Moreover, the existence of spin-polarized superconducting components was implied by the conductance measurement using the hetero-structures.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Coinvestigator, 22560001

Fundamental research on spin-dependent functional devices based on half-metallic ferromagnet/semiconductor hybrid structures
Grants-in-Aid for Scientific Research(基盤研究(B))
2009 - 2011
Tetsuya UEMURA; Masafumi YAMAMOTO; Ken-ichi MATSUDA
The purpose of this research project was to develop fundamental technologies for creation of viable spintronic devices, in which electron spins are utilized as an additional degree of freedom for information and storage. For that purpose we demonstrated highly-efficient spin injection from halfmetallic ferromanet of Co-based Heusler alloy into GaAs and Si. Furthermore we clarified spin-dependent transport properties through the investigation of spin lifetime and interplay between electron spins and nuclear spins in the semiconductor channels.
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 北海道大学, Principal investigator, Competitive research funding, 21360140

Fabrication of high-quality heterostructures with half-metallic ferromagnets and creation of spin tunneling devices
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
2008 - 2010
YAMAMOTO Masafumi; TETSUYA Uemura; MATSUDA KenーIchi
Heusler alloy thin films are promising as ferromagnetic electrode materials because they feature high spin polarization arising from their potentially half-metallic nature. High-quality heterostructures with Heusler alloy thin films were developed for device applications. Given these heterostructures, excellent devices characteristics were demonstrated for magnetic tunnel junctions. Furthermore, giant oscillations in spin-dependent tunneling resistances as a function of barrier thickness were found for fully epitaxial magnetic tunnel junctions with Heusler alloy Co2Cr0.6Fe0.4Al electrodes and a MgO barrier.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 20246054

Exploration and creation of highly efficient spin sources using half-metallic ferromagnets
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas
2007 - 2010
YAMAMOTO Masafumi; TETSUYA Uemura; MATSUDA Ken-ichi
A highly efficient spin-polarized electron source or spin source is a key element for spintronic devices, in which both the charge and the spin of the electron are utilized as the information carrier. Heusler alloys thin films have attracted much interest as spin sources because of the half-metallic nature theoretically predicted for many of these alloys. It was found that detrimental defects can be reduced by appropriately controlling the film composition of Heusler alloys. It was also shown that the suppression of detrimental defects led to a significant enhancement of the half-metallic nature of Heusler alloy thin films in device structures. Excellent device characteristics were demonstrated for fabricated magnetic tunnel junctions with Heusler alloy electrodes and a MgO barrier by improving the interfacial structures in addition to the above-mentioned enhancement of the half-metallic nature.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Priority Areas, Hokkaido University, 19048001

Study on spin dependent transport in ferromagnet/semiconductor heterostructures
Grants-in-Aid for Scientific Research(基盤研究(C))
2007 - 2008
Tetsuya UEMURA
半導体中の伝導電子のスピンを操作し、これまでにない新しい機能を有する電子/光デバイスの研究が盛んに行われている。その実現の第一歩は、スピン偏極した電子を半導体内に発生させることであり、強磁性電極から半導体にスピン偏極した電子を電気的に注入する方法(スピン注入)が有効である。本研究では、高効率スピン注入の実現に向け、スピン偏極率の高いハーフメタル材料であるCo系ホイスラー合金薄膜を半導体GaAs上に高品質に形成するとともに、ホイスラー合金/GaAsヘテロ接合構造におけるスピン依存伝導特性を明らかにした。このことにより、将来の新しいスピン機能デバイスの創出にむけた基盤技術を確立した。
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(C), 北海道大学, Principal investigator, Competitive research funding, 19560307

Fabrication of epitaxial heterostructures with halrf-metallic ferromagnets and development of spin-controlled devices
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
2006 - 2007
YAMAMOTO Masafumi; UEMURA Tetsuya; MATSUDA Ken-ichi; SAITO Toshiaki
The purpose of the present study was to develop spintronic devices utilizing the half-metallicity of Co-based Heusler alloys (Co_2YZ). Fully epitaxial magnetic tunnel junctions (MTJs) with a Co_2YZ thin film or Co_2YZ thin films and a MgO barrier featuring abrupt and extremely smooth interfaces were fabricated. Furthermore, high tunnel magnetoresistance (TMR) ratios were demonstrated at room temperature (RT) for fabricated Co_2YZ/MgO-based MTJs. The main results are summarized as follows.
1) The Heusler alloy-based MTJ device technology was developed. This device technology features the followings: a) all layers in the MTJ trilayer structures are epitaxial and single-crystalline, b) abrupt and atomically flat interfaces between a Co_2YZ (Co_2Cr_<0.6>Fe_<0.4>Al (CCFA), Co_2MnSi (CMS), or Co_2MnGe) thin film and a MgO tunnel barrier, and c) the interface region of CMS thin films underneath a MgO barrier is not oxidized.
2) The fabricated CCFA/MgO/Co_<50>Fe_<50> MTJs demonstrated a high TMR ratio of 109 % at RT (317% at 4.2 K).
3) Fully epitaxial exchange-biased MTJs with CMS thin films as both lower and upper electrodes and with a MgO barrier were fabricated.
The TMR ratios at both RT and 4.2 K increased with increasing the in-situ annealing temperature (T_a) just after the deposition of the upper CMS electrode. Furthermore, a high TMR ratio of 179% at RT (683% at 4.2 K) was demonstrated.
In summary, it was demonstrated that epitaxial, single-crystalline heterostructures consisting of Co_2YZ thin films and a MgO barrier are highly promising for spintronic devices that utilize the half-metallicity of Co-based Heusler alloys.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 18360143

Fabrication of epitaxial, magnetic multiple-barrier-structures and development of spin-resonant-tunneling -device basic technology
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
2004 - 2005
YAMAMOTO Masafumi; UEMURA Tetsuya; MATSUDA Ken-ichi
Cobalt-based full-Heusler alloy thin films have recently attracted much interest as highly desirable ferromagnetic electrodes for spintronic devices because of the half-metallic ferromagnetic nature theoretically predicted for some of these alloys, and because of their high Curie temperatures, which are well above room temperature (RT). In this study, Co-based full-Heusler alloy thin films of Co_2Cr_<0.6>Fe_<0.4>Al (CCFA) and Co_2MnGe (CMG) were epitaxially grown on MgO-buffered MgO (001) substrates using magnetron sputtering. The films were deposited at RT and subsequently annealed in situ at temperatures ranging from 400 to 600℃. The annealed films of CCFA and CMG had sufficiently flat surface morphologies with roughness of about 0.25-nm rms. Using these epitaxially grown thin films, we fabricated fully epitaxial magnetic tunnel junctions (MTJs) consisting of a Co-based full-Heusler thin film of either CCFA or CMG as a lower electrode, a MgO tunnel barrier, and a Co_<50>Fe_<50> (CoFe) upper electrode. The microfabricated epitaxial CCFA/MgO/CoFe MTJs demonstrated relatively high tunnel magnetoresistance (TMR) ratios of 42% at RT and 74% at 55K. These results confirm the promise of epitaxial MTJs as a key device structure for utilizing the potentially high spin-polarization of Co-based full-Heusler alloy thin films. We also fabricated epitaxial double-barrier-structures consisting of CCFA/MgO/Co_<50>Fe_<50>/MgO/Co_<50>Fe_<50>. The fabricated double-barrier-structures showed TMR ratios comparable with that of single-barrier structures consisting of CCFA/MgO/Co_<50>Fe_<50> and V_ (the bias voltage at which the TMR ratio fell to half the zero-bias value) twice as high as that of the single-barrier structures. In summary, we have developed basic fabrication technologies for epitaxial, magnetic multiple-barrier-structures.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), HOKKAIDO UNIVERSITY, Coinvestigator, 16360143

Development of novel circuits consisting of magnetic tunnel junction and negative differential resistance devices
Grants-in-Aid for Scientific Research(基盤研究(C))
2004 - 2005
Tetsuya UEMURA
The objective of this project is to develop novel magnetic random access memory (MRAM) cells consisting of magnetic tunnel junction (MTJ) and negative differential resistance (NDR) devices, such as an interband tunnel diode (ITD) or a resonant tunnel diode (RTD), connected in parallel or in series. The NDR characteristics of the ITD or RTD can increase the tunneling magnetoresistance (TMR) ratio of the MTJ. The peak voltages (currents) of the NDR characteristics are changed depending on the magnetization directions of the MTJ when the NDR device is connected in series (parallel), resulting in large MR ratio.We successfully confirmed the basic operation of the proposed memory cells by both simulation and experiment. The fabricated circuit consisting of the CoFe based MTJ and GaAs based tunnel diode showed that the effective MR ratio was enhanced from its original value of 15 to 890% in the series circuit.We also optimized the device structures. As for the MTJs, we fabricated the MTJs using half-metallic materials, such as Co-based full Heusler alloys, Perovskite-type manganites, or ferromagnetic semiconductors, and achieved relatively high TMR ratios of up to 90% at room temperature. The use of MTJs with its original TMR ratio of more than 50% results in sufficient operating margin of the bias current/voltage. As for the NDR devices, we fabricated the GaAs-based RTD with high peak-to-valley current ratio.We developed the SPICE models for both MTJs and tunnel diodes based on the experimental results and analyzed that how the circuit performance, such as cell area, access speed, power dissipation, and operating margin, would be changed as increasing the integration density of the memory cell. Furthermore, we designed the power supply circuit based on the reference cell architecture, which was robust to the variation of device characteristics, and successfully confirmed its proper operation.
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(C), 北海道大学, Principal investigator, Competitive research funding, 16560289

Study of ferromagnetic multiple-tunnel-junction devices
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
2001 - 2002
YAMAMOTO Masafumi; UEMURA Tetsuya; AMEMIYA Yoshihito
Novel devices based on the concept of utilizing spin dependent resonant tunneling phenomena were investigated. The device characteristics of a resonant tunneling magnetic random access memory (MRAM) using a ferromagnetic triple-barrier structure in which both of two quantum wells are composed of ferromagnetic metals were analyzed. Calculations showed that the resonant tunneling memory consisting of a ferromagnetic triple-barrier structure could provide an exceedingly high reading current ratio for "1" and "0" of an order of 10^4%. This property is highly promising for nonvolatile ultrahigh-density spin-memory. Furthermore, we proposed and analysed a resonant tunneling spin filter, which is one of key devices for emerging spintronics, consisting of a ferromagnetic GaMnAs-based quantum well (QW) and a non-magnetic GaAs QW. Detailed calculations showed that it could produce high spin-polarized currents with polarizations exceeding 98 %.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Coinvestigator, 13450132

Faculty of Information Science and Technology　Electronics for Informatics　Advanced Electronics	Professor
Institute for Frontier Education and Research on Semiconductors	Professor