博士(工学), 東北大学

スピントロニクス

spintronics

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

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

Mar. 2007, 東北大学大学院工学研究科, 「電気・情報優秀賞」(博士)
山ノ内 路彦

Sep. 2006, 応用物理学会, 第20回応用物理学会 講演奨励賞
山ノ内 路彦

Dec. 2005, 財団法人青葉工学振興会, 第11回研究奨励賞
山ノ内 路彦

Single-Layer Spin-Orbit-Torque Magnetization Switching Due to Spin Berry Curvature Generated by Minute Spontaneous Atomic Displacement in a Weyl Oxide.
Hiroto Horiuchi; Yasufumi Araki; Yuki K Wakabayashi; Jun'ichi Ieda; Michihiko Yamanouchi; Yukio Sato; Shingo Kaneta-Takada; Yoshitaka Taniyasu; Hideki Yamamoto; Yoshiharu Krockenberger; Masaaki Tanaka; Shinobu Ohya
Advanced materials (Deerfield Beach, Fla.), e2416091, 24 Apr. 2025, [International Magazine]
English, Scientific journal, Spin Berry curvature characterizes the band topology as the spin counterpart of Berry curvature and is crucial in generating novel spintronics functionalities. By breaking the crystalline inversion symmetry, the spin Berry curvature is expected to be significantly enhanced; this enhancement will increase the intrinsic spin Hall effect in ferromagnetic materials and, thus, the spin-orbit torques (SOTs). However, this intriguing approach is not applied to devices; generally, the spin Hall effect in ferromagnet/heavy-metal bilayer is used for SOT magnetization switching. Here, SOT-induced partial magnetization switching is demonstrated in a single layer of a single-crystalline Weyl oxide SrRuO3 (SRO) with a small current density of ≈3.1 × 106 A cm-2. Detailed analysis of the crystal structure in the seemingly perfect periodic lattice of the SRO film reveals barely discernible oxygen octahedral rotations with angles of ≈5° near the interface with a substrate. Tight-binding calculations indicate that a large spin Hall conductivity is induced around small gaps generated at band crossings by the synergy of inherent spin‒orbit coupling and band inversion due to the rotations, causing magnetization reversal. The results indicate that a minute atomic displacement in single-crystal films can induce strong intrinsic SOTs that are useful for spin-orbitronics devices.

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, 12 Mar. 2025
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.

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
English, Scientific journal

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, 14 Jun. 2023, [Peer-reviewed]
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.

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, 30 Jan. 2023, [Peer-reviewed]
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.

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, 345003, IOP Publishing, 25 Aug. 2022
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.

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, 01 Aug. 2022
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, American Association for the Advancement of Science (AAAS), 15 Apr. 2022
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 induced magnetization switching for an ultrathin MnGa/Co2MnSi bilayer
Kohey Jono; Fumiaki Shimohashi; Michihiko Yamanouchi; Tetsuya Uemura
AIP Advances, 11, 2, 025205, 025205, AIP Publishing, 01 Feb. 2021, [Peer-reviewed]
Scientific journal

Current-induced effective magnetic field in La0.67Sr0.33MnO3/LaAlO3/SrTiO3 structures
Michihiko Yamanouchi; Tatsuro Oyamada; Hiromichi Ohta
AIP Advances, 10, 015129, 14 Jan. 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, Dec. 2019, [Peer-reviewed]
English, Scientific journal

Interaction between spin-orbit torque and domain walls in a Ta/MnGa/NiAl structure
Michihiko Yamanouchi; Nguyen Viet Bao; Masaki Inoue; Tetsuya Uemura
JAPANESE JOURNAL OF APPLIED PHYSICS, 58, 10, Oct. 2019, [Peer-reviewed]
English, Scientific journal

Peculiar magnetotransport properties in La0.67Sr0.33MnO3/LaAlO3/SrTiO3
Michihiko Yamanouchi; Tatsuro Oyamada; Hiromichi Ohta
AIP Advances, 9, 035129, Mar. 2019, [Peer-reviewed]
English, Scientific journal

Current-induced modulation of coercive field in the ferromagnetic oxide SrRuO3
Michihiko Yamanouchi; Tatsuro Oyamada; Koichi Sato; Hiromichi Ohta; Jun’ichi Ieda
IEEE Transactions on Magnetics, 1400604, Feb. 2019, [Peer-reviewed]
English, Scientific journal

Gate tunable spin-orbit coupling and weak antilocalization effect in an epitaxial La2/3Sr1/3MnO3 thin film
Shao-Pin Chiu; Michihiko Yamanouchi; Tatsuro Oyamada; Hiromichi Ohta; Juhn-Jong Lin
PHYSICAL REVIEW B, 96, 8, 085143-1, 085143-7, Aug. 2017, [Peer-reviewed]
English, Scientific journal

Adiabatic spin-transfer-torque-induced domain wall creep in a magnetic metal
S. DuttaGupta; S. Fukami; C. Zhang; H. Sato; M. Yamanouchi; F. Matsukura; H. Ohno
NATURE PHYSICS, 12, 4, 333, U167, Apr. 2016, [Peer-reviewed]
English, Scientific journal

Solid-Phase Epitaxial Growth of A-Site-Ordered Perovskite Sr4-xErxCo4O12-delta: A Room Temperature Ferrimagnetic p-Type Semiconductor
Takayoshi Katase; Hidefumi Takahashi; Tetsuya Tohei; Yuki Suzuki; Michihiko Yamanouchi; Yuichi Ikuhara; Ichiro Terasaki; Hiromichi Ohta
ADVANCED ELECTRONIC MATERIALS, 1, 12, 1500199, Dec. 2015, [Peer-reviewed]
English, Scientific journal

Dependence of magnetic properties of MgO/CoFeB/Ta stacks on CoFeB and Ta thicknesses
Kyota Watanabe; Shinya Ishikawa; Hideo Sato; Shoji Ikeda; Michihiko Yamanouchi; Shunsuke Fukami; Fumihiro Matsukura; Hideo Ohno
JAPANESE JOURNAL OF APPLIED PHYSICS, 54, 4, 04EM04, Apr. 2015, [Peer-reviewed]
English, Scientific journal

In-plane anisotropy of a nano-scaled magnetic tunnel junction with perpendicular magnetic easy axis
Eriko Hirayama; Shun Kanai; Koji Sato; Michihiko Yamanouchi; Hideo Sato; Shoji Ikeda; Fumihiro Matsukura; Hideo Ohno
JAPANESE JOURNAL OF APPLIED PHYSICS, 54, 4, 04EM03, Apr. 2015, [Peer-reviewed]
English, Scientific journal

Perpendicular-anisotropy CoFeB-MgO based magnetic tunnel junctions scaling down to 1X nm
S. Ikeda; H. Sato; H. Honjo; E. C.I. Enobio; S. Ishikawa; M. Yamanouchi; S. Fukami; S. Kanai; F. Matsukura; T. Endoh; H. Ohno
Technical Digest - International Electron Devices Meeting, IEDM, 2015-, February, 33.2.1, 33.2.4, Institute of Electrical and Electronics Engineers Inc., 20 Feb. 2015, [Peer-reviewed]
English, International conference proceedings

Localized precessional mode of domain wall controlled by magnetic field and dc current
Ryo Hiramatsu; Kab-Jin Kim; Takuya Taniguchi; Takayuki Tono; Takahiro Moriyama; Shunsuke Fukami; Michihiko Yamanouchi; Hideo Ohno; Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS EXPRESS, 8, 2, 023003, Feb. 2015, [Peer-reviewed]
English, Scientific journal

Domain Wall Motion Device for Nonvolatile Memory and Logic - Size Dependence of Device Properties
Shunsuke Fukami; Michihiko Yamanouchi; Shoji Ikeda; Hideo Ohno
IEEE TRANSACTIONS ON MAGNETICS, 50, 11, 6971556, Nov. 2014, [Peer-reviewed]
English, Scientific journal

Properties of magnetic tunnel junctions with a MgO/CoFeB/Ta/CoFeB/MgO recording structure down to junction diameter of 11nm
H. Sato; E. C.I. Enobio; M. Yamanouchi; S. Ikeda; S. Fukami; S. Kanai; F. Matsukura; H. Ohno
Applied Physics Letters, 105, 6, 11 Aug. 2014
English, Scientific journal

Interface control of the magnetic chirality in CoFeB/MgO heterostructures with heavy-metal underlayers
Jacob Torrejon; Junyeon Kim; Jaivardhan Sinha; Seiji Mitani; Masamitsu Hayashi; Michihiko Yamanouchi; Hideo Ohno
NATURE COMMUNICATIONS, 5, Aug. 2014, [Peer-reviewed]
English, Scientific journal

Electric-field effects on magnetic anisotropy and damping constant in Ta/CoFeB/MgO investigated by ferromagnetic resonance
A. Okada; S. Kanai; M. Yamanouchi; S. Ikeda; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 105, 5, Aug. 2014, [Peer-reviewed]
English, Scientific journal

Influence of Heavy Ion Irradiation on Perpendicular-Anisotropy CoFeB-MgO Magnetic Tunnel Junctions
Daisuke Kobayashi; Yuya Kakehashi; Kazuyuki Hirose; Shinobu Onoda; Takahiro Makino; Takeshi Ohshima; Shoji Ikeda; Michihiko Yamanouchi; Hideo Sato; Eli Christopher Enobio; Tetsuo Endoh; Hideo Ohno
IEEE TRANSACTIONS ON NUCLEAR SCIENCE, 61, 4, 1710, 1716, Aug. 2014, [Peer-reviewed]
English, Scientific journal

Magnetization reversal induced by in-plane current in Ta/CoFeB/MgO structures with perpendicular magnetic easy axis
C. Zhang; M. Yamanouchi; H. Sato; S. Fukami; S. Ikeda; F. Matsukura; H. Ohno
Journal of Applied Physics, 115, 17, 07 May 2014
Scientific journal

Anomalous temperature dependence of current-induced torques in CoFeB/MgO heterostructures with Ta-based underlayers
Junyeon Kim; Jaivardhan Sinha; Seiji Mitani; Masamitsu Hayashi; Saburo Takahashi; Sadamichi Maekawa; Michihiko Yamanouchi; Hideo Ohno
PHYSICAL REVIEW B, 89, 17, 174424, May 2014, [Peer-reviewed]
English, Scientific journal

Magnetization switching in a CoFeB/MgO magnetic tunnel junction by combining spin-transfer torque and electric field-effect
S. Kanai; Y. Nakatani; M. Yamanouchi; S. Ikeda; H. Sato; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 104, 21, 212406, May 2014, [Peer-reviewed]
English, Scientific journal

Co/Pt multilayer-based magnetic tunnel junctions with a CoFeB/Ta insertion layer
S. Ishikawa; H. Sato; M. Yamanouchi; S. Ikeda; S. Fukami; F. Matsukura; H. Ohno
JOURNAL OF APPLIED PHYSICS, 115, 17, 17C719, May 2014, [Peer-reviewed]
English, Scientific journal

Distribution of critical current density for magnetic domain wall motion
S. Fukami; M. Yamanouchi; Y. Nakatani; K. -J. Kim; T. Koyama; D. Chiba; S. Ikeda; N. Kasai; T. Ono; H. Ohno
JOURNAL OF APPLIED PHYSICS, 115, 17, 17D508, May 2014, [Peer-reviewed]
English, Scientific journal

Co/Pt multilayer based reference layers in magnetic tunnel junctions for nonvolatile spintronics VLSIs
Hideo Sato; Shoji Ikeda; Shunsuke Fukami; Hiroaki Honjo; Shinya Ishikawa; Michihiko Yamanouchi; Kotaro Mizunuma; Fumihiro Matsukura; Hideo Ohno
JAPANESE JOURNAL OF APPLIED PHYSICS, 53, 4, 04EM02, Apr. 2014, [Peer-reviewed]
English, Scientific journal

Quantitative characterization of the spin-orbit torque using harmonic Hall voltage measurements
Masamitsu Hayashi; Junyeon Kim; Michihiko Yamanouchi; Hideo Ohno
PHYSICAL REVIEW B, 89, 14, 144425, Apr. 2014, [Peer-reviewed]
English, Scientific journal

MgO/CoFeB/Ta/CoFeB/MgO recording structure with low intrinsic critical current and high thermal stability
H. Sato; M. Yamanouchi; S. Ikeda; S. Fukami; F. Matsukura; H. Ohno
Journal of the Magnetics Society of Japan, 38, No. 2-2, 56, 60, 20 Mar. 2014, [Peer-reviewed]
English, Scientific journal

Effect of spin Hall torque on current-induced precessional domain wall motion
Yoko Yoshimura; Tomohiro Koyama; Daichi Chiba; Yoshinobu Nakatani; Shunsuke Fukami; Michihiko Yamanouchi; Hideo Ohno; Kab-Jin Kim; Takahiro Moriyama; Teruo Ono
APPLIED PHYSICS EXPRESS, 7, 3, 033005, Mar. 2014, [Peer-reviewed]
English, Scientific journal

Advances in Spintronics Devices for Microelectronics - From Spin-transfer Torque to Spin- orbit Torque
S. Fukami; H. Sato; M. Yamanouchi; S. Ikeda; F. Matsukura; H. Ohno
2014 19TH ASIA AND SOUTH PACIFIC DESIGN AUTOMATION CONFERENCE (ASP-DAC), 684, 691, 2014, [Peer-reviewed]
English, International conference proceedings

Electric Field-Induced Magnetization Switching in CoFeB-MgO-Static Magnetic Field Angle Dependence
Shun Kanai; Michihiko Yamanouchi; Shoji Ikeda; Yoshinobu Nakatani; Fumihiro Matsukura; Hideo Ohno
IEEE TRANSACTIONS ON MAGNETICS, 50, 1, article number 4200103, Jan. 2014, [Peer-reviewed]
English, Scientific journal

Magnetotransport measurements of current induced effective fields in Ta/CoFeB/MgO
Chaoliang Zhang; Michihiko Yamanouchi; Hideo Sato; Shunsuke Fukami; Shoji Ikeda; Fumihiro Matsukura; Hideo Ohno
APPLIED PHYSICS LETTERS, 103, 26, 262407, Dec. 2013, [Peer-reviewed]
English, Scientific journal

Influence of heavy ion irradiation on perpendicular-anisotropy CoFeB-MgO magnetic tunnel junctions
Daisuke Kobayashi; Yuya Kakehashi; Kazuyuki Hirose; Shinobu Onoda; Takahiro Makino; Takeshi Ohshima; Shoji Ikeda; Michihiko Yamanouchi; Hideo Sato; Eli Christopher Enobio; Tetsuo Endoh; Hideo Ohno
Proceedings of the European Conference on Radiation and its Effects on Components and Systems, RADECS, 28 Oct. 2013, [Peer-reviewed]
English, International conference proceedings

Demonstration of a Nonvolatile Processor Core Chip with Software-Controlled Three-Terminal MRAM Cells for Standby-Power Critical Applications
R. Nebashi; Y. Tsuji; H. Honjo; N. Sakimura; A. Morioka; K. Tokutome; S. Miura; S. Fukami; M. Yamanouchi; K. Kinoshita; T. Hanyu; T. Endoh; N. Kasai; H. Ohno; T. Sugibayashi
2013 International Conference on Solid State Devices and Materials (SSDM), M-8-3, 1102, 1103, 24 Sep. 2013, [Peer-reviewed]
English, International conference proceedings

In-plane magnetic field dependence of electric field-induced magnetization switching
S. Kanai; Y. Nakatani; M. Yamanouchi; S. Ikeda; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 103, 7, 072408, Aug. 2013, [Peer-reviewed]
English, Scientific journal

Depinning probability of a magnetic domain wall in nanowires by spin-polarized currents
S. Fukami; M. Yamanouchi; S. Ikeda; H. Ohno
NATURE COMMUNICATIONS, 4, 2293, Aug. 2013, [Peer-reviewed]
English, Scientific journal

CoNi Films with Perpendicular Magnetic Anisotropy Prepared by Alternate Monoatomic Layer Deposition
Shunsuke Fukami; Hideo Sato; Michihiko Yamanouchi; Shoji Ikeda; Hideo Ohno
APPLIED PHYSICS EXPRESS, 6, 7, 073010, Jul. 2013, [Peer-reviewed]
English, Scientific journal

MgO/CoFeB/Ta/CoFeB/MgO Recording Structure in Magnetic Tunnel Junctions With Perpendicular Easy Axis
Hideo Sato; Michihiko Yamanouchi; Shoji Ikeda; Shunsuke Fukami; Fumihiro Matsukura; Hideo Ohno
IEEE TRANSACTIONS ON MAGNETICS, 49, 7, 4437, 4440, Jul. 2013, [Peer-reviewed]
English, Scientific journal

Electrical endurance of Co/Ni wire for magnetic domain wall motion device
S. Fukami; M. Yamanouchi; H. Honjo; K. Kinoshita; K. Tokutome; S. Miura; S. Ikeda; N. Kasai; H. Ohno
Applied Physics Letters, 102, 22, 222410, 03 Jun. 2013, [Peer-reviewed]
English, Scientific journal

Size dependence of magnetic properties of nanoscale CoFeB-MgO magnetic tunnel junctions with perpendicular magnetic easy axis observed by ferromagnetic resonance
Kotaro Mizunuma; Michihiko Yamanouchi; Hideo Sato; Shoji Ikeda; Shun Kanai; Fumihiro Matsukura; Hideo Ohno
Applied Physics Express, 6, 6, 063002, Jun. 2013, [Peer-reviewed]
English, Scientific journal

Enhanced interface perpendicular magnetic anisotropy in Ta vertical bar CoFeB vertical bar MgO using nitrogen doped Ta underlayers
Jaivardhan Sinha; Masamitsu Hayashi; Andrew J. Kellock; Shunsuke Fukami; Michihiko Yamanouchi; Hideo Sato; Shoji Ikeda; Seiji Mitani; See-hun Yang; Stuart S. P. Parkin; Hideo Ohno
APPLIED PHYSICS LETTERS, 102, 24, 242405, Jun. 2013, [Peer-reviewed]
English, Scientific journal

Two-barrier stability that allows low-power operation in current-induced domain-wall motion
Kab-Jin Kim; Ryo Hiramatsu; Tomohiro Koyama; Kohei Ueda; Yoko Yoshimura; Daichi Chiba; Kensuke Kobayashi; Yoshinobu Nakatani; Shunsuke Fukami; Michihiko Yamanouchi; Hideo Ohno; Hiroshi Kohno; Gen Tatara; Teruo Ono
NATURE COMMUNICATIONS, 4, 2011, Jun. 2013, [Peer-reviewed]
English, Scientific journal

Three terminal magnetic tunnel junction utilizing the spin Hall effect of iridium-doped copper
Michihiko Yamanouchi; Lin Chen; Junyeon Kim; Masamitsu Hayashi; Hideo Sato; Shunsuke Fukami; Shoji Ikeda; Fumihiro Matsukura; Hideo Ohno
APPLIED PHYSICS LETTERS, 102, 21, 212408, May 2013, [Peer-reviewed]
English, Scientific journal

Magnetic properties of MgO-[Co/Pt] multilayers with a CoFeB insertion layer
S. Ishikawa; H. Sato; M. Yamanouchi; S. Ikeda; S. Fukami; F. Matsukura; H. Ohno
JOURNAL OF APPLIED PHYSICS, 113, 17, 17C721, May 2013, [Peer-reviewed]
English, Scientific journal

Layer thickness dependence of the current-induced effective field vector in Ta vertical bar CoFeB vertical bar MgO
Junyeon Kim; Jaivardhan Sinha; Masamitsu Hayashi; Michihiko Yamanouchi; Shunsuke Fukami; Tetsuhiro Suzuki; Seiji Mitani; Hideo Ohno
NATURE MATERIALS, 12, 3, 240, 245, Mar. 2013, [Peer-reviewed]
English, Scientific journal

Low-current domain wall motion MRAM with perpendicularly magnetized CoFeB/MgO magnetic tunnel junction and underlying hard magnets
T. Suzuki; H. Tanigawa; Y. Kobayashi; K. Mori; Y. Ito; Y. Ozaki; K. Suemitsu; T. Kitamura; K. Nagahara; E. Kariyada; N. Ohshima; S. Fukami; M. Yamanouchi; S. Ikeda; M. Hayashi; M. Sakao; H. Ohno
Digest of Technical Papers - Symposium on VLSI Technology, 2013
International conference proceedings

Comprehensive study of CoFeB-MgO magnetic tunnel junction characteristics with single- and double-interface scaling down to 1X nm
H. Sato; T. Yamamoto; M. Yamanouchi; S. Ikeda; S. Fukami; K. Kinoshita; F. Matsukura; N. Kasai; H. Ohno
2013 IEEE INTERNATIONAL ELECTRON DEVICES MEETING (IEDM), 6724550, 2013, [Peer-reviewed]
English, International conference proceedings

Spin
S. Ikeda; H. Sato; M. Yamanouchi; H. Gan; K. Miura; K. Mizunuma; S. Kanai; S. Fukami; F. Matsukura; N. Kasai; H. Ohno
Recent progress of perpendicular anisotropy magnetic tunnel junctions for nonvolatile VLSI, 2, 3, 1240003(1), 1240003(12), 04 Dec. 2012, [Peer-reviewed]
English, Scientific journal

Recent progress of perpendicular anisotropy magnetic tunnel junctions for nonvolatile VLSI
S. Ikeda; H. Sato; M. Yamanouchi; H. Gan; K. Miura; K. Mizunuma; S. Kanai; S. Fukami; F. Matsukura; N. Kasai; H. Ohno
SPIN, 2, 1240003, Dec. 2012, [Peer-reviewed]
Scientific journal

Boron Composition Dependence of Magnetic Anisotropy and Tunnel Magnetoresistance in MgO/CoFe(B) Based Stack Structures
Shoji Ikeda; Ryohei Koizumi; Hideo Sato; Michihiko Yamanouchi; Katsuya Miura; Kotaro Mizunuma; Huadong Gan; Fumihiro Matsukura; Hideo Ohno
IEEE TRANSACTIONS ON MAGNETICS, 48, 11, 3829, 3832, Nov. 2012, [Peer-reviewed]
English, Scientific journal

Electric field-induced magnetization reversal in a perpendicular-anisotropy CoFeB-MgO magnetic tunnel junction
S. Kanai; M. Yamanouchi; S. Ikeda; Y. Nakatani; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 101, 12, 022414, Sep. 2012, [Peer-reviewed]
English, Scientific journal

Scalability Prospect of Three-Terminal Magnetic Domain-Wall Motion Device
Shunsuke Fukami; Nobuyuki Ishiwata; Naoki Kasai; Michihiko Yamanouchi; Hideo Sato; Shoji Ikeda; Hideo Ohno
IEEE TRANSACTIONS ON MAGNETICS, 48, 7, 2152, 2157, Jul. 2012, [Peer-reviewed]
English, Scientific journal

Observation of magnetic domain-wall dynamics transition in Co/Ni multilayered nanowires
Kab-Jin Kim; D. Chiba; K. Kobayashi; S. Fukami; M. Yamanouchi; H. Ohno; Soong-Geun Je; Sug-Bong Choe; T. Ono
APPLIED PHYSICS LETTERS, 101, 2, 022407, Jul. 2012, [Peer-reviewed]
English, Scientific journal

Current-Induced Domain Wall Motion in Perpendicularly Magnetized Co/Ni Nanowire under In-Plane Magnetic Fields
Yoko Yoshimura; Tomohiro Koyama; Daichi Chiba; Yoshinobu Nakatani; Shunsuke Fukami; Michihiko Yamanouchi; Hideo Ohno; Teruo Ono
APPLIED PHYSICS EXPRESS, 5, 6, 063001, Jun. 2012, [Peer-reviewed]
English, Scientific journal

Spatial control of magnetic anisotropy for current induced domain wall injection in perpendicularly magnetized CoFeB vertical bar MgO nanostructures
Masamitsu Hayashi; Michihiko Yamanouchi; Shunsuke Fukami; Jaivardhan Sinha; Seiji Mitani; Hideo Ohno
APPLIED PHYSICS LETTERS, 100, 19, 192411, May 2012, [Peer-reviewed]
English, Scientific journal

Domain wall dynamics driven by spin transfer torque and the spin-orbit field
Masamitsu Hayashi; Yoshinobu Nakatani; Shunsuke Fukami; Michihiko Yamanouchi; Seiji Mitani; Hideo Ohno
JOURNAL OF PHYSICS-CONDENSED MATTER, 24, 2, 024221, Jan. 2012, [Peer-reviewed]
English, Scientific journal

CoFeB Thickness Dependence of Thermal Stability Factor in CoFeB/MgO Perpendicular Magnetic Tunnel Junctions
H. Sato; M. Yamanouchi; K. Miura; S. Ikeda; R. Koizumi; F. Matsukura; H. Ohno
IEEE MAGNETICS LETTERS, 3, 3000204, 2012, [Peer-reviewed]
English, Scientific journal

Origin of the collapse of tunnel magnetoresistance at high annealing temperature in CoFeB/MgO perpendicular magnetic tunnel junctions
H. D. Gan; H. Sato; M. Yamanouchi; S. Ikeda; K. Miura; R. Koizumi; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 99, 25, 252507, Dec. 2011, [Peer-reviewed]
English, Scientific journal

Junction size effect on switching current and thermal stability in CoFeB/MgO perpendicular magnetic tunnel junctions
H. Sato; M. Yamanouchi; K. Miura; S. Ikeda; H. D. Gan; K. Mizunuma; R. Koizumi; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 99, 4, 042501, Jul. 2011, [Peer-reviewed]
English, Scientific journal

Tunnel Magnetoresistance Properties of Double MgO-Barrier Magnetic Tunnel Junctions With Different Free-Layer Alloy Compositions and Structures
Huadong Gan; Shoji Ikeda; Michihiko Yamanouchi; Katsuya Miura; Kotaro Mizunuma; Jun Hayakawa; Fumihiro Matsukura; Hideo Ohno
IEEE TRANSACTIONS ON MAGNETICS, 47, 6, 1567, 1570, Jun. 2011, [Peer-reviewed]
English, Scientific journal

Tunnel magnetoresistance properties and annealing stability in perpendicular anisotropy MgO-based magnetic tunnel junctions with different stack structures
K. Mizunuma; S. Ikeda; H. Sato; M. Yamanouchi; H. D. Gan; K. Miura; H. Yamamoto; J. Hayakawa; F. Matsukura; H. Ohno
JOURNAL OF APPLIED PHYSICS, 109, 7, 07C711, Apr. 2011, [Peer-reviewed]
English, Scientific journal

Current-induced effective field in perpendicularly magnetized Ta/CoFeB/MgO wire
T. Suzuki; S. Fukami; N. Ishiwata; M. Yamanouchi; S. Ikeda; N. Kasai; H. Ohno
APPLIED PHYSICS LETTERS, 98, 14, 142502, Apr. 2011, [Peer-reviewed]
English, Scientific journal

Dependence of magnetic anisotropy on MgO thickness and buffer layer in Co20Fe60B20-MgO structure
M. Yamanouchi; R. Koizumi; S. Ikeda; H. Sato; K. Mizunuma; K. Miura; H. D. Gan; F. Matsukura; H. Ohno
Journal of Applied Physics, 109, 7, 07C712-(1), 07C712-(3), 01 Apr. 2011, [Peer-reviewed]
English, International conference proceedings

Pd Layer Thickness Dependence of Tunnel Magnetoresistance Properties in CoFeB/MgO-Based Magnetic Tunnel Junctions with Perpendicular Anisotropy CoFe/Pd Multilayers
Kotaro Mizunuma; Michihiko Yamanouchi; Shoji Ikeda; Hideo Sato; Hiroyuki Yamamoto; Hua-Dong Gan; Katsuya Miura; Jun Hayakawa; Fumihiro Matsukura; Hideo Ohno
APPLIED PHYSICS EXPRESS, 4, 2, 023002, Feb. 2011, [Peer-reviewed]
English, Scientific journal

Current-induced domain wall motion in perpendicularly magnetized CoFeB nanowire
S. Fukami; T. Suzuki; Y. Nakatani; N. Ishiwata; M. Yamanouchi; S. Ikeda; N. Kasai; H. Ohno
APPLIED PHYSICS LETTERS, 98, 8, 082504, Feb. 2011, [Peer-reviewed]
English, Scientific journal

Domain Structure in CoFeB Thin Films With Perpendicular Magnetic Anisotropy
Michihiko Yamanouchi; Albrecht Jander; Pallavi Dhagat; Shoji Ikeda; Fumihiro Matsukura; Hideo Ohno
IEEE MAGNETICS LETTERS, 2, 3000304, 2011, [Peer-reviewed]
English, Scientific journal

CoFeB/MgO based perpendicular magnetic tunnel junctions with stepped structure for symmetrizing different retention times of "0" and "1" information
K. Miura; S. Ikeda; M. Yamanouchi; H. Yamamoto; K. Mizunuma; H. D. Gan; J. Hayakawa; R. Koizumi; F. Matsukura; H. Ohno
Digest of Technical Papers - Symposium on VLSI Technology, 214, 215, 2011
English, International conference proceedings

A 32-Mb SPRAM With 2T1R Memory Cell, Localized Bi-Directional Write Driver and '1'/'0' Dual-Array Equalized Reference Scheme
Riichiro Takemura; Takayuki Kawahara; Katsuya Miura; Hiroyuki Yamamoto; Jun Hayakawa; Nozomu Matsuzaki; Kazuo Ono; Michihiko Yamanouchi; Kenchi Ito; Hiromasa Takahashi; Shoji Ikeda; Haruhiro Hasegawa; Hideyuki Matsuoka; Hideo Ohno
IEEE JOURNAL OF SOLID-STATE CIRCUITS, 45, 4, 869, 879, Apr. 2010, [Peer-reviewed]
English, Scientific journal

SPRAM with large thermal stability for high immunity to read disturbance and long retention for high-temperature operation
K. Ono; T. Kawahara; R. Takemura; K. Miura; M. Yamanouchi; J. Hayakawa; K. Ito; H. Takahashi; H. Matsuoka; S. Ikeda; H. Ohno
2009 Symposium on VLSI Technology, 228, 229, Jun. 2009, [Peer-reviewed]
English

32-Mb 2T1R SPRAM with localized bi-directional write driver and ‘1’/‘0’ dual-array equalized reference cell
R. Takemura; T. Kawahara; K. Miura; H. Yamamoto; J. Hayakawa; N. Matsuzaki; K. Ono; M. Yamanouchi; K. Ito; H. Takahashi; S. Ikeda; H. Hasegawa; H. Matsuoka; H. Ohno
2009 Symposium on VLSI Circuits, 84, 85, Jun. 2009, [Peer-reviewed]
English

A disturbance-free read scheme and a compact stochastic-spin-dynamics-based MTJ circuit model for Gb-scale SPRAM
K. Ono; T. Kawahara; R. Takemura; K. Miura; H. Yamamoto; M. Yamanouchi; J. Hayakawa; K. Ito; H. Takahashi; S. Ikeda; H. Hasegawa; H. Matsuoka; H. Ohno
Technical Digest - International Electron Devices Meeting, IEDM, 9.3.4, 9.3.4, 2009, [Peer-reviewed]
English, International conference proceedings

Current-induced magnetization switching in MgO barrier magnetic tunnel junctions with CoFeB-based synthetic ferrimagnetic free layers
Jun Hayakawa; Shoji Ikeda; Katsuya Miura; Michihiko Yarnanouchi; Young Min Lee; Ryutaro Sasaki; Masahiko Ichimura; Kenchi Ito; Takayuki Kawahara; Riichiro Takemura; Toshiyasu Meguro; Fumihiro Matsukura; Hiromasa Takahashi; Hideyuki Matsuoka; Hideo Ohno
IEEE TRANSACTIONS ON MAGNETICS, 44, 7, 1962, 1967, Jul. 2008, [Peer-reviewed]
English, Scientific journal

TMR Design Methodology for SPin-Transfer Torque RAM (SPRAM) with Nonvolatile and SRAM Compatible Operations
R. Takemura; T. Kawahara; J. Hayakawa; K. Miura; K. Ito; M. Yamanouchi; S. Ikeda; H. Takahashi; H. Matsuoka; H. Ohno
Joint Non-Volatile Semiconductor Memory Workshop 2008, and 2008 International Conference on Memory Technology and Design (NVSMW/ICMTD), 54, 54, 56, May 2008, [Peer-reviewed]
English

Universality classes for domain wall motion in the ferromagnetic semiconductor (Ga, Mn)As
M. Yamanouchi; J. Ieda; F. Matsukura; S. E. Barnes; S. Maekawa; H. Ohno
SCIENCE, 317, 5845, 1726, 1729, Sep. 2007, [Peer-reviewed]
English, Scientific journal

Switching of tunnel magnetoresistance by domain wall motion in (Ga,Mn)As-based magnetic tunnel junctions
M. Fukuda; M. Yamanouchi; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 91, 5, 052503, Jul. 2007, [Peer-reviewed]
English, Scientific journal

Domain wall resistance in perpendicularly magnetized (Ga,Mn) As
D. Chiba; M. Yamanouchi; F. Matsukura; T. Dietl; H. Ohno
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 310, 2, 2078, 2083, Mar. 2007, [Peer-reviewed]
English, Scientific journal

Current-assisted domain wall motion in ferromagnetic semiconductors
Michihiko Yamanouchi; Daichi Chiba; Fumihiro Matsukura; Hideo Ohno
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 45, 5A, 3854, 3859, May 2006, [Peer-reviewed]
English, Scientific journal

Velocity of domain-wall motion induced by electrical current in the ferromagnetic semiconductor (Ga,Mn)As
M Yamanouchi; D Chiba; F Matsukura; T Dietl; H Ohno
PHYSICAL REVIEW LETTERS, 96, 9, 096601, Mar. 2006, [Peer-reviewed]
English, Scientific journal

Domain-wall resistance in ferromagnetic (Ga,Mn)As
D Chiba; M Yamanouchi; F Matsukura; T Dietl; H Ohno
PHYSICAL REVIEW LETTERS, 96, 9, 096602, Mar. 2006, [Peer-reviewed]
English, Scientific journal

Current-induced domain-wall switching in a ferromagnetic semiconductor structure
M. Yamanouchi; D. Chiba; F. Matsukura; H. Ohno
Nature, 428, 6982, 539, 541, 01 Apr. 2004, [Peer-reviewed]
English, Scientific journal

Control of magnetization reversal in ferromagnetic semiconductors by electrical means
Chiba, D; Yamanouchi, M; Matsukura, F; Ohno, H
Journal of Physics-Condensed Matter, 16, 48, S5693, S5696, 2004, [Peer-reviewed]
English, Scientific journal

Electrical magnetization reversal in ferromagnetic semiconductors
Matsukura, F; Chiba, D; Yamanouchi, M; Ohno, H; Badawy, W; Moussa, W
2004 International Conference on Mems, Nano and Smart Systems, Proceedings, 128, 128, 2004, [Peer-reviewed]
Scientific journal

Electrical manipulation of magnetization reversal in a ferromagnetic semiconductor
D. Chiba; H. Yamanouchi; F. Hatsukura; H. Ohno
Science, 301, 5635, 943, 945, 15 Aug. 2003, [Peer-reviewed]
English, Scientific journal

Electric field effect on the magnetic properties of III-V ferromagnetic semiconductor (In, Mn)As and ((Al),Ga,Mn)As
D Chiba; M Yamanouchi; F Matsukura; E Abe; Y Ohno; K Ohtani; H Ohno
JOURNAL OF SUPERCONDUCTIVITY, 16, 1, 179, 182, Feb. 2003, [Peer-reviewed]
English, Scientific journal

Electric field effect on the magnetic properties of III-V ferromagnetic semiconductor (In,Mn)As and ((Al),Ga,Mn)As
D. Chiba; M. Yamanouchi; F. Matsukura; E. Abe; Y. Ohno; K. Ohtani; H. Ohno
Journal of Superconductivity and Novel Magnetism, 16, 1, 179, 182, 2003
English, Scientific journal

Electric Field Control of Ferromagnetism in III-V Ferromagnetic Semiconductor
D. Chiba; M. Yamanouchi; F. Matsukura; Y. Ohno; K. Ohtani; H. Ohno
Proceedings of the 26th International Conference on the Physics of Semiconductor, F2.2, Jul. 2002, [Peer-reviewed]
English, International conference proceedings, <RIEC><DUMMY>あ</DUMMY><BIBID>2003500425</BIBID></RIEC>

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, 2025年 第72回応用物理学会春季学術講演会 予稿集, Mar. 2025, [Corresponding author]

Thickness-dependent magnetization switching induced by spin-orbit torque in Weyl ferromagnet SrRuO3 single-layer films
Hiroto Horiuchi; Wakabayashi Yuki K.; Araki Yasufumi; Ieda Jun'ichi; Yamanouchi Michihiko; Kaneta-Takada Shingo; Taniyasu Yoshitaka; Yamamono Hideki; Krockenberger Yoshiharu; Tanaka Masaaki; Ohya Shinobu, The 72nd JSAP Spring Meeting 2025, Mar. 2025

Effective magnetic field by orbital torque in Pd/Co2MnGa perpendicular magnetization films
Takaya Koyama; Kenta Watanabe; Tetsuya Uemura; Michihiko Yamanouchi, The 72nd JSAP Spring Meeting 2025, Mar. 2025, [Corresponding author]

Thickness dependence of current-induced effective magnetic field acting on domain wall in SrRuO3
Kanata Nakamura; Tomoki Shibata; Takaya Koyama; Tetsuya Uemura; Michihiko Yamanouchi, The 72nd JSAP Spring Meeting 2025 abstract, Mar. 2025, [Corresponding author]

Observations of Non-Local Spin-Valve Signal and Hanle Signal in Perpendicularly MagnetizedMn/Co/n-GaAs Junctions via All Electrical Methods
Mineto Ogawa; Kotaro Nara; Michihiko Yamanouchi; Tetsuya Uemura, The 16th Joint Conference on Magnetism and Magnetic Materials and Intermag abstract, Jan. 2025, [Peer-reviewed]

In-plane magnetic field dependence of torque exerted on a domain wall in Pd/Co MnGa
Takaya Koyama; Yuki Nishioka; Tetsuya Uemura; Michihiko Yamanouchi, The 16th Joint Conference on Magnetism and Magnetic Materials and Intermag abstract, Jan. 2025, [Peer-reviewed], [Corresponding author]

Spin-orbit-torque magnetization switching in a ferromagnetic SrRuO3 single layer with a spontaneous oxygen atomic displacement
Hiroto Horiuchi; Wakabayashi Yuki K.; Araki Yasufumi; Ieda Jun'ichi; Yamanouchi Michihiko; Kaneta-Takada Shingo; Taniyasu Yoshitaka; Yamamono Hideki; Krockenberger Yoshiharu; Tanaka Masaaki; Ohya Shinobu, The 85th JSAP Autumn Meeting 2024, Sep. 2024

Electrical spin injection into GaAs from perpendicularly magnetized Mn/Co bilayers
Kotaro Nara; Mineto Ogawa; Michihiko Yamanouchi; Tetsuya Uemura, The 85th JSAP Autumn Meeting 2024 abstract, Sep. 2024

Spin torque originating from Weyl electrons in ferromagnetic oxide SrRuO₃
山ノ内路彦, 日本物理学会講演概要集(CD-ROM), 78, 2, 2023

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

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, 04 Sep. 2019
The Japan Society of Applied Physics, English

Sign reversal of current-induced effective magnetic field in La_0.67Sr_0.33MnO₃ heterostructures
Yamanouchi Michihiko; Oyamada Tatsuro; Ohta Hiromichi, JSAP Annual Meetings Extended Abstracts, 2019.1, 1900, 1900, 25 Feb. 2019
The Japan Society of Applied Physics, English

Anomalous magneto-transports of La_0.67Sr_0.33MnO₃/2DES-LaAlO₃/SrTiO₃
Oyamada Tatsuro; Ohta Hiromichi; Yamanouchi Michihiko, JSAP Annual Meetings Extended Abstracts, 2018.2, 2021, 2021, 05 Sep. 2018
The Japan Society of Applied Physics, Japanese

Thickness Dependence of Current-Induced Effective Magnetic Field in La_0.67Sr_0.33MnO₃/SrTiO₃ heterostructure
Oyamada Tatsuro; Katase Takayoshi; Ohta Hiromichi; Yamanouchi Michihiko, JSAP Annual Meetings Extended Abstracts, 2017.1, 2047, 2047, 01 Mar. 2017
The Japan Society of Applied Physics, Japanese

Current-induced effects on switching magnetic field in La_0.67Sr_0.33MnO₃/SrTiO₃
Yamanouchi Michihiko; Oyamada Tatsuro; Katase Takayoshi; Ohta Hiromichi, JSAP Annual Meetings Extended Abstracts, 2016.2, 1933, 1933, 01 Sep. 2016
The Japan Society of Applied Physics, Japanese

Influence of spin Hall effect for current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire
Yoshimura Y.; Koyama T.; Moriyama T.; Kim Kab-Jin; Chiba D.; Nakatani Y.; Fukami S.; Yamanouchi M.; Ohno H.; Ono T., Meeting abstracts of the Physical Society of Japan, 68, 2, 415, 415, 26 Aug. 2013
The Physical Society of Japan (JPS), Japanese

27pXA-6 Current pulse width dependence of magnetic domain wall motion in the presence of bias magnetic field
Kim Kab-Jin; Chiba D.; Nakatani Y.; Fukami S.; Yamanouchi M.; Ohno H.; Ono T., Meeting abstracts of the Physical Society of Japan, 68, 1, 540, 540, 26 Mar. 2013
The Physical Society of Japan (JPS), English

20aCC-10 Current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire under in-plane magnetic field (II)
Yoshimura Y.; Koyama T.; Chiba D.; Fukami S.; Yamanouchi M.; Ohno H.; Nakatani Y.; Ono T., Meeting abstracts of the Physical Society of Japan, 67, 2, 427, 427, 24 Aug. 2012
The Physical Society of Japan (JPS), Japanese

27aAA-9 Current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire under in-plane magnetic field
Yoshimura Y; Koyama T; Chiba D; Fukami S; Yamanouchi M; Ohno H; Nakatani Y; Ono T, Meeting Abstracts of the Physical Society of Japan, 67, 0, 533, 533, 2012
The Physical Society of Japan, Japanese

High-speed and reliable domain wall motion device: Material design for embedded memory and logic application
S. Fukami; M. Yamanouchi; T. Koyama; K. Ueda; Y. Yoshimura; K. J. Kim; D. Chiba; H. Honjo; N. Sakimura; R. Nebashi; Y. Kato; Y. Tsuji; A. Morioka; K. Kinoshita; S. Miura; T. Suzuki; H. Tanigawa; S. Ikeda; T. Sugibayashi; N. Kasai; T. Ono; H. Ohno, Digest of Technical Papers - Symposium on VLSI Technology, 61, 62, 2012
English

Current-Induced Domain Wall Motion in Ferromagnetic Semiconductor Structures
CHIBA D.; YAMANOUCHI M.; MATSUKURA F.; OHNO H., Magnetics Japan, 4, 8, 390, 395, 01 Aug. 2009
日本磁気学会, Japanese

22aWB-7 Domain Wall Creep Motion in a Ferromagnetic Semiconductor (Ga,Mn)As (Experiment)
Matsukura F.; Yamanouchi M.; Ohno H., Meeting abstracts of the Physical Society of Japan, 62, 2, 452, 452, 21 Aug. 2007
The Physical Society of Japan (JPS), Japanese

SPRAM (SPin-transfer torque RAM) with a synthetic ferrimagnetic free layer for suppressing read disturbance and write-current dispersion
MIURA Katsuya; KAWAHARA Takayuki; TAKEMURA Riichiro; HAYAKAWA Jun; YAMANOUCHI Michihiko; IKEDA Shoji; SASAKI Ryutaro; ITO Kenchi; TAKAHASHI Hiromasa; MATSUOKA Hideyuki; OHNO Hideo, IEICE technical report, 107, 194, 135, 138, 16 Aug. 2007
SPin-transfer torque RAM(SPRAM) with MgO-barrier-based magnetic tunnel junctions (MTJs) is a promising candidate for a future universal memory due to its non-volatility, high-speed operation and low power consumption. The read disturbance and the write-current dispersion of an MTJ could be suppressed by adopting a free layer with high thermal stability. We found that SPRAM with SyF free layer demonstrates the secure reading and writing and achieves the high-speed reading faster than 1.5ns., The Institute of Electronics, Information and Communication Engineers, Japanese

Domain wall and transport in ferromagnetic semiconductor
千葉 大地; 山ノ内 路彦; 松倉 文礼, Solid state physics, 42, 2, 99, 106, Feb. 2007
アグネ技術センタ-, Japanese

Current Induced Magnetization Switching in (Ga, Mn)As MTJs
CHIBA D.; KITA T.; YAMANOUCHI M.; MATSUKURA F.; OHNO H., 日本応用磁気学会研究会資料, 145, 7, 12, 30 Jan. 2006
Japanese

27aYP-5 Current induced domain wall propagation in a ferromagnetic semiconductor structure fabricated by patterning of coercive force
Yamanouchi Michihiko; Chiba Daichi; Matsukura Fumihiro; Ohno Yuzo; Ohno Hideo, Meeting abstracts of the Physical Society of Japan, 60, 1, 481, 481, 04 Mar. 2005
The Physical Society of Japan (JPS), Japanese

強磁性の電界制御
千葉 大地; 山ノ内 路彦; 松倉 文礼, 固体物理, 38, 9, 612, 618, Sep. 2003
アグネ技術センタ-, Japanese

強磁性酸化物SrRuO3におけるワイル電子に起因したスピントルク
山ノ内路彦
日本物理学会第78回年次大会, 17 Sep. 2023, Nominated symposium
[Invited]

Effects of spin-orbit torque on domain wall motion in Ta/MnGa/NiAl structure
M. Yamanouchi; N. V. Bao; M. Inoue; T. Uemura
64th Annual Conference on Magnetism and Magnetic Materials (2019 MMM Conference), 08 Nov. 2019, Oral presentation

Current-induced effective magnetic field in La0.67Sr0.33MnO3/LaAlO3/SrTiO3
M. Yamanouchi; T. Oyamada; H. Ohta
64th Annual Conference on Magnetism and Magnetic Materials (2019 MMM Conference), 05 Nov. 2019, Oral presentation

強磁性酸化物における電流誘起有効磁場
山ノ内路彦
強的秩序とその操作に関わる第9回研究会－若手夏の学校－, 16 Sep. 2019, Invited oral presentation

Effects of current on domain wall motion in SrRuO3
M. Yamanouchi; T. Oyamada; K. Sato; H. Ohta; J. Ieda
2019 Joint MMM-Intermag Conference, Jan. 2019, Poster presentation
14 Jan. 2019 - 18 Jan. 2019

Anomalous magnetotransport properties of La0.67Sr0.33MnO3/LaAlO3/SrTiO3
M. Yamanouchi; T. Oyamada; H. Ohta
2019 Joint MMM-Intermag Conference, Poster presentation
14 Jan. 2019 - 18 Jan. 2019

Current-induced modulation of switching magnetic field in La0.67Sr0.33MnO3/SrTiO3 structures
M. Yamanouchi; T. Oyamada; T. Katase; H. Ohta
61st Annual Conference on Magnetism and Magnetic Materials (2016 MMM Conference), 2016, Oral presentation
31 Oct. 2016 - 04 Nov. 2016

Quantitative determination of intrinsic energy barrier for current induced domain wall motion
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

Influence of in-plane magnetic fields on current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

Current-induced effective field vector in Ta│CoFeB│MgO with various layer thicknesses
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

Temperature dependence of spin polarization in Co/Ni nanowires with different Co and Ni thicknesses determined from magnetic domain wall dynamics
8th International Symposium on Metallic Multilayers (MML2013), 2013

Monoatomically-layered CoNi film with perpendicular magnetic anisotropy
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

(Co100-xFex)80B20 composition dependence of interface anisotropy in MgO/CoFeB/Ta stack structure
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

MgO/CoFeB/Ta/CoFeB/MgO recording structure with low critical current and high thermal stability
JSPS York-Tohoku Symposium on Magnetic Materials and Spintronic Devices, 2013

Low-Current Domain Wall Motion MRAM with Perpendicularly Magnetized CoFeB/MgO Magnetic Tunnel Junction and Underlying Hard Magnets
2013 Symposia on VLSI Circuits, 2013

垂直磁気異方性CoFeB-MgO磁気トンネル接合のトンネル磁気抵抗特性の温度依存性
第32回電子材料シンポジウム(EMS32), 2013, Poster presentation

Electric-field induced magnetization switching in CoFeB-MgO with different magnetic field angles
International Symposium on Advanced Magnetic Materials and Applications (ISAMMA), 2013

Electrical reliability of Co/Ni wire for domain wall motion devices
International Symposium on Advanced Magnetic Materials and Applications (ISAMMA), 2013

CuIrチャネルを用いた3端子磁気トンネル接合
東北大学電気通信研究所ナノ・スピン実験施設研究発表会, 2013

Spin hall effect in switching of three terminal magnetic tunnel junction with culr channel
Joint European Magnetic Symposia (JEMS), 2013

垂直磁気異方性CoNi超格子膜の作製と磁気特性の評価
第37回日本磁気学会学術講演会, 2013

Co/Ni細線における磁壁デピニング確率の測定と計算
第37回日本磁気学会学術講演会, 2013

Tuneable chiral domain wall motion by intertwined spin Hall effect and spin transfer torque in ultrathin TaN/CoFeB/MgO
Donostia International Conference on Nanoscaled Magnetism and Applications (ICNMA), 2013

Co/Pt multilayer based reference layers in magnetic tunnel junction for novolatile spintronics VLSIs
International Conference on Solid State Devices and Materials (SSDM), 2013

Demonstration of a nonvolatile processor core chip with software-controlled trhee-terminal MRAM cells for standby-power critical applications
International Conference on Solid State Devices and Materials (SSDM), 2013

垂直磁化Co/Ni細線中の磁壁電流駆動におけるスピンホール効果の影響
日本物理学会秋季大会, 2013

Distribution of critical current density for magnetic domain wall motion
58th Magnetism and Magnetic Materials (MMM), 2013

Magnetization reversal induced by in-plane current in Ta/CoFeB/MgO structures with perpendicular magnetic easy axis
58th Magnetism and Magnetic Materials (MMM), 2013

Co/Pt multilayer-based magnetic tunnel junctions with thin Ta spacer layer
58th Magnetism and Magnetic Materials (MMM), 2013

Temperature dependence of thermal stability factor of CoFeB-MgO magnetic tunnel junctions with perpendicular easy-axis
58th Magnetism and Magnetic Materials (MMM), 2013

Two-barrier stability in current-induced domain-wall motion device
58th Magnetism and Magnetic Materials (MMM), 2013, Poster presentation

Cuベースチャネル3端子磁気トンネル接合
応用物理学会スピントロニクス研究会・日本磁気学会スピンエレクトロニクス専門研究会共同主催研究会「元素戦略、環境調和を視野に入れたスピントロニクスの新展開」, 2013

垂直磁化容易CoFeB-MgO磁気トンネル接合における電流誘起磁化反転の面内磁場依存性
応用物理学会東北支部講演会, 2013

MgO/Fe(B)/MgO積層膜の磁気特性
応用物理学会東北支部講演会, 2013

Temperature dependence of electric-field effects on magnetic anisotropies in Ta-CoFeB-MgO
Physics and Applications of Spin-related Phenomena in Semiconductors (PASPS-18), 2013, Poster presentation

20-nm magnetic domain wall motion memory with ultralow-power operation
2013 IEEE International Electron Devices Meeting (IEDM), 2013

Comprehensive study of CoFeB-MgO magnetic tunnel junction characteristics with single- and double-interface scaling down to 1X nm
2013 IEEE International Electron Devices Meeting (IEDM), 2013

Quantitative determination of intrinsic energy barrier for current induced domain wall motion
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

Influence of in-plane magnetic fields on current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

Current-induced effective field vector in Ta│CoFeB│MgO with various layer thicknesses
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

Temperature dependence of spin polarization in Co/Ni nanowires with different Co and Ni thicknesses determined from magnetic domain wall dynamics
8th International Symposium on Metallic Multilayers (MML2013), 2013

Monoatomically-layered CoNi film with perpendicular magnetic anisotropy
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

(Co100-xFex)80B20 composition dependence of interface anisotropy in MgO/CoFeB/Ta stack structure
8th International Symposium on Metallic Multilayers (MML2013), 2013, Poster presentation

MgO/CoFeB/Ta/CoFeB/MgO recording structure with low critical current and high thermal stability
JSPS York-Tohoku Symposium on Magnetic Materials and Spintronic Devices, 2013

Low-Current Domain Wall Motion MRAM with Perpendicularly Magnetized CoFeB/MgO Magnetic Tunnel Junction and Underlying Hard Magnets
2013 Symposia on VLSI Circuits, 2013

垂直磁気異方性CoFeB-MgO磁気トンネル接合のトンネル磁気抵抗特性の温度依存性
第32回電子材料シンポジウム(EMS32), 2013, Poster presentation

Electric-field induced magnetization switching in CoFeB-MgO with different magnetic field angles
International Symposium on Advanced Magnetic Materials and Applications (ISAMMA), 2013

Electrical reliability of Co/Ni wire for domain wall motion devices
International Symposium on Advanced Magnetic Materials and Applications (ISAMMA), 2013

CuIrチャネルを用いた3端子磁気トンネル接合
東北大学電気通信研究所ナノ・スピン実験施設研究発表会, 2013

Spin hall effect in switching of three terminal magnetic tunnel junction with culr channel
Joint European Magnetic Symposia (JEMS), 2013

垂直磁気異方性CoNi超格子膜の作製と磁気特性の評価
第37回日本磁気学会学術講演会, 2013

Co/Ni細線における磁壁デピニング確率の測定と計算
第37回日本磁気学会学術講演会, 2013

Tuneable chiral domain wall motion by intertwined spin Hall effect and spin transfer torque in ultrathin TaN/CoFeB/MgO
Donostia International Conference on Nanoscaled Magnetism and Applications (ICNMA), 2013

Co/Pt multilayer based reference layers in magnetic tunnel junction for novolatile spintronics VLSIs
International Conference on Solid State Devices and Materials (SSDM), 2013

Demonstration of a nonvolatile processor core chip with software-controlled trhee-terminal MRAM cells for standby-power critical applications
International Conference on Solid State Devices and Materials (SSDM), 2013

垂直磁化Co/Ni細線中の磁壁電流駆動におけるスピンホール効果の影響
日本物理学会秋季大会, 2013

Distribution of critical current density for magnetic domain wall motion
58th Magnetism and Magnetic Materials (MMM), 2013

Magnetization reversal induced by in-plane current in Ta/CoFeB/MgO structures with perpendicular magnetic easy axis
58th Magnetism and Magnetic Materials (MMM), 2013

Co/Pt multilayer-based magnetic tunnel junctions with thin Ta spacer layer
58th Magnetism and Magnetic Materials (MMM), 2013

Temperature dependence of thermal stability factor of CoFeB-MgO magnetic tunnel junctions with perpendicular easy-axis
58th Magnetism and Magnetic Materials (MMM), 2013

Two-barrier stability in current-induced domain-wall motion device
58th Magnetism and Magnetic Materials (MMM), 2013, Poster presentation

Cuベースチャネル3端子磁気トンネル接合
応用物理学会スピントロニクス研究会・日本磁気学会スピンエレクトロニクス専門研究会共同主催研究会「元素戦略、環境調和を視野に入れたスピントロニクスの新展開」, 2013

垂直磁化容易CoFeB-MgO磁気トンネル接合における電流誘起磁化反転の面内磁場依存性
応用物理学会東北支部講演会, 2013

MgO/Fe(B)/MgO積層膜の磁気特性
応用物理学会東北支部講演会, 2013

Temperature dependence of electric-field effects on magnetic anisotropies in Ta-CoFeB-MgO
Physics and Applications of Spin-related Phenomena in Semiconductors (PASPS-18), 2013, Poster presentation

20-nm magnetic domain wall motion memory with ultralow-power operation
2013 IEEE International Electron Devices Meeting (IEDM), 2013

Comprehensive study of CoFeB-MgO magnetic tunnel junction characteristics with single- and double-interface scaling down to 1X nm
2013 IEEE International Electron Devices Meeting (IEDM), 2013

Thickness dependence of thermal stability factor in CoFeB/MgO perpendicular magnetic tunnel junctions
International Magnetics Conference (INTERMAG), 2012

CoFeB composition dependence of magnetic anisotropy and tunnel magnetoresistance in CoFeB/MgO stack structures
International Magnetics Conference (INTERMAG), 2012

Factors Determining Thermal Stability in CoFeB-MgO Perpendicular Junctions
9th RIEC International Workshop on Spintronics, 2012

Electromotive Forces in (Ga, Mn)As-based Structures
9th RIEC International Workshop on Spintronics, 2012

Magnetic Anisotropy of Co/Pt based Electrodes for Magnetic Tunnel Junctions with perpendicular Magnetic Easy Axis
9th RIEC International Workshop on Spintronics, 2012, Poster presentation

High-Speed and Reliable Domain Wall Motion Device: Material Design for Embedded Memory and Logic Application
2012 Symposium on VLSI Technology, 2012

Retention time under currents and magnetic fields in a CoFeB/MgO perpendicular magnetic tunnel junction
19th International Conference on Magnetism (ICM2012), 2012, Poster presentation

垂直磁気トンネル接合におけるCo/Pt電極の磁気異方性のPt膜厚および熱処理温度依存性
第31回電子材料シンポジウム, 2012

Perpendicular CoFeB-MgO magnetic tunnel junction
SPIE Nanoscience+Engineering 2012, 2012

CoFeB-MgO垂直磁化容易磁気トンネル接合における強磁性共鳴のホモダイン検出
第73回応用物理学会学術講演会, 2012

MgO/CoFeB/Ta/CoFeB/MgO構造を用いた垂直磁気容易磁気トンネル接合
第73回応用物理学会学術講演会, 2012, Poster presentation

垂直磁気異方性CoFeB-MgO接合における電界誘起磁化反転
第73回応用物理学会学術講演会, 2012

Domain wall depinning probability - Experiment and Theory
21th International Colloquium on Magnetic Films and Surfaces (ICMFS), 2012, Poster presentation

Ferromagnetic resonance by means of homodyne detection technique in CoFeB/MgO magnetic tunnel junctions with perpendicular easy axis
21th International Colloquium on Magnetic Films and Surfaces (ICMFS), 2012, Poster presentation

Magnetic Anisotropy in CoFe(B)/MgO Stack Structures
International Conference of the Asian Union of Magnetics Societies (ICAUMS), 2012, Poster presentation

Spintronics devices for nonvolatile memory and logic
12th Non-Volatile Memory Technology Symposium (NVMTS), 2012

Thickness dependence of thermal stability factor in CoFeB/MgO perpendicular magnetic tunnel junctions
International Magnetics Conference (INTERMAG), 2012

CoFeB composition dependence of magnetic anisotropy and tunnel magnetoresistance in CoFeB/MgO stack structures
International Magnetics Conference (INTERMAG), 2012

Factors Determining Thermal Stability in CoFeB-MgO Perpendicular Junctions
9th RIEC International Workshop on Spintronics, 2012

Electromotive Forces in (Ga, Mn)As-based Structures
9th RIEC International Workshop on Spintronics, 2012

Magnetic Anisotropy of Co/Pt based Electrodes for Magnetic Tunnel Junctions with perpendicular Magnetic Easy Axis
9th RIEC International Workshop on Spintronics, 2012, Poster presentation

High-Speed and Reliable Domain Wall Motion Device: Material Design for Embedded Memory and Logic Application
2012 Symposium on VLSI Technology, 2012

Retention time under currents and magnetic fields in a CoFeB/MgO perpendicular magnetic tunnel junction
19th International Conference on Magnetism (ICM2012), 2012, Poster presentation

垂直磁気トンネル接合におけるCo/Pt電極の磁気異方性のPt膜厚および熱処理温度依存性
第31回電子材料シンポジウム, 2012

Perpendicular CoFeB-MgO magnetic tunnel junction
SPIE Nanoscience+Engineering 2012, 2012

CoFeB-MgO垂直磁化容易磁気トンネル接合における強磁性共鳴のホモダイン検出
第73回応用物理学会学術講演会, 2012

MgO/CoFeB/Ta/CoFeB/MgO構造を用いた垂直磁気容易磁気トンネル接合
第73回応用物理学会学術講演会, 2012, Poster presentation

垂直磁気異方性CoFeB-MgO接合における電界誘起磁化反転
第73回応用物理学会学術講演会, 2012

Domain wall depinning probability - Experiment and Theory
21th International Colloquium on Magnetic Films and Surfaces (ICMFS), 2012, Poster presentation

Ferromagnetic resonance by means of homodyne detection technique in CoFeB/MgO magnetic tunnel junctions with perpendicular easy axis
21th International Colloquium on Magnetic Films and Surfaces (ICMFS), 2012, Poster presentation

Magnetic Anisotropy in CoFe(B)/MgO Stack Structures
International Conference of the Asian Union of Magnetics Societies (ICAUMS), 2012, Poster presentation

Spintronics devices for nonvolatile memory and logic
12th Non-Volatile Memory Technology Symposium (NVMTS), 2012

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

応用数学Ⅱ, 2024年, 学士課程, 工学部

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
30 Jun. 2022 - 31 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, 22K18961

ワイル点を有する強磁性体における電流誘起磁壁移動
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
Apr. 2020 - Mar. 2023
山ノ内 路彦
本研究では、ワイル点を有する強磁性体においてワイル点が電流誘起磁壁移動に与える効果を明らかにすることを主目的としている。本年度は、フェルミ準位近傍にワイル点を有する強磁性体SrRuO3において、前年度より広い範囲で温度を変え、ワイル点とフェルミ準位の相対的位置を系統的に変化させた時に電流が磁壁に及ぼす有効磁場がどのように変化するかを詳細に調べることにより、本研究の目的の達成をめざした。その結果、単位電流当たりに誘起される有効磁場は温度に対して2つのピークをもつ特異な温度依存性を示し、かつその大きさは強磁性金属で報告されている値よりも2桁程度大きいことがわかった。これらの結果は従来機構では説明できないため、SrRuO3における電流誘起磁壁移動はこれまでに観測されていない新たな機構に関係していると推察された。そのような中で、最近になって、フェルミ準位近傍にワイル点を有する強磁性体においては、磁壁を横切るように電界を印加すると、ワイル点近傍のワイルフェルミオンによってトポロジカルホールトルクと呼ばれる新規のトルクが磁壁に作用することが理論的に示され、本研究で観測された有効磁場との関連が期待された。実験結果とトポロジカルホールトルクによる有効磁場の理論計算を比較したところ、この有効磁場の特異な温度依存性、及び大きさは、ともにトポロジカルホールトルクで説明できることがわかった。これらの結果から、ワイル点を有する強磁性体においては、ワイルフェルミオンに起因したトポロジカルホールトルクによって、高効率な電流誘起磁壁移動や特異な温度依存性を示す電流誘起磁壁移動が発現すると考えられる。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 20H02598

Searching for new materials functions by atomic layer control
Grants-in-Aid for Scientific Research
28 Jun. 2013 - 31 Mar. 2018
Ohta Hiromichi; KATASE TAKAYOSHI; YAMANOUCHI MICHIHIKO
In this study, we fabricated “Nano-layers”, which are thin films controlled in the thickness at the atomic level. We searched for new materials functions, and worked on the development of Nanostructure information by providing the nano-layers to other groups. The major results are listed below. [1] We successfully enhanced the thermoelectric power factor of oxide-based superlattices double compared with the bulk. [2] We clarified the origin of carrier mobility suppression of a transparent oxide semiconductor and successfully realized high carrier mobility. [3] We found that two-dimensional electron gas in semiconductor shows high thermoelectric power factor. [4] We realized thin-film devices, which can switch their optical transmission, electrical resistivity, and magnetic properties simultaneously. [5] We realized iron-based superconducting films on the metallic tapes, which showed high critical current density suitable as practical applications.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Hokkaido University, 25106007

酸化物ヘテロ構造におけるスピン軌道トルク
科学研究費補助金(若手研究(A) )
Apr. 2015 - Mar. 2017
山ノ内路彦
文部科学省, Principal investigator, Competitive research funding

Formation and transport of persistent spin helix state in GaAs/AlGaAs quantum wires
Grants-in-Aid for Scientific Research
01 Apr. 2012 - 31 Mar. 2014
OHNO Yuzo; YAMANOUCHI Michihiko
Spin-orbit interaction (SOI) plays important roles in the field of spintronics because the SOI field enables for spin manipulation and causes spin relaxation. In this study, using time-resolved Kerr rotation measurement, we investigate ensemble spin dynamics in wires made from a modulation-doped AlGaAs/GaAs QW in which both Dresselhaus and Rashba SOIs coexist. In addition, we perform the time- and spatially-resolved Kerr rotation measurement to observe the spatiotemporal evolution of photoexcited spins, and demonstrated gate-controlled spin distribution of a two-dimensional electron gas with a top gate electrode.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, University of Tsukuba, 24656003

Control and detection of spin dynamics in semiconductor/ferromagent hybrid structures
Grants-in-Aid for Scientific Research
18 Nov. 2011 - 31 Mar. 2014
OHNO Yuzo; YAMANOUCHI Michihiko
We fabricated three-terminal devices which have a CoFeB/MgO/GaAs magnetic tunnel junction with perpendicular magnetization, and performed magnetotransport and Kerr microscopy measurements to clarify the generation and detection of spin accumulation in GaAs semiconductors. In magnetotransport measurements, we observed typical Hanle effect. However, in Kerr microscopy measurements, the Kerr rotation signal remains even in high in-plane magnetic fields : Bx =+/- 2.0 T. The results suggest that the interface between MgO and GaAs plays crucial role for perpendicular spin injection.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), 23246002

Intrinsic pinning in in-plane magnetized film
Grants-in-Aid for Scientific Research
2012 - 2013
YAMANOUCHI Michihiko
To determine the intrinsic pinning and extrinsic pinning dependences of threshold current for the current-induced domain wall motion in in-plane magnetized films, fabrication method of stacking structure and device structure was studied. I proposed a fabrication method of films realizing that the extrinsic pinning is weaker than the intrinsic pinning and device structure to prepare a domain wall in in-plane magnetized wire by using Oersted field. An in-plane magnetized wire having an Oersted field line to create a domain wall was fabricated.
Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Tohoku University, Principal investigator, Competitive research funding, 24760249

スピン注入磁壁移動の機構と応用に関する研究
科学研究費助成事業
2003 - 2005
山ノ内 路彦
今年度は、強磁性半導体ガリウムマンガン砒素における電流誘起磁壁移動の機構を調べるために、面直方向に磁化容易軸をもつガリウムマンガン砒素において、電流誘起磁壁移動速度の電流密度依存性および温度依存性を測定し、現在提案されている理論との比較を行った。まず、磁壁移動速度を評価するための素子作成を行った。バッファ層として、徐々にインジウム組成を変えたインジウムアルミニウム砒素を用いることにより、転位に起因した表面の凹凸を低減した。幅5μmのチャネルを形成した後、チャネル表面を部分的にエッチングすることにより、面内に保磁力の異なる2つの領域を作製した。磁壁移動速度の評価は以下のように行った。保磁力差を利用して外部磁場により、領域境界に磁壁を配置した後、電流パルスを印加して磁壁を移動させた。磁壁の位置はカー効果偏光顕微鏡を用いて観察した。磁壁が掃引した面積をチャネル幅で割ったものを実効磁壁移動距離d_と定義し、d_のパルス幅w_p依存性を測定した。d_はw_pに対してほぼ線形に変化することが分かった。そこで、その傾きを実効磁壁移動速度v_と定義し、v_の電流密度jおよび温度T_a依存性を測定した。v_はjとT_aの関数で10^<-4>〜10^1m/sオーダにわたって制御可能であり、そのj依存性には少なくとも2つの領域があることが分かった。高電流密度領域(>3x10^5 A/cm^2)においては、v_はjにほぼ線形に変化し、最高で22m/sの磁壁移動速度が得られた。理論との比較から、この領域の電流誘起磁壁移動機構はキャリアスピンから局在磁気スピンへのスピンのトランスファによって説明できることが分かった。低電流密度領域においては、v_のj依存性は現象論的なスケーリング則に従い、電流により磁壁のクリープが誘起されていると考えられる
日本学術振興会, 特別研究員奨励費, 東北大学, 03J50091

垂直磁化磁気抵抗効果素子及び磁気メモリ
Patent right, 大野 英男; 池田 正二; 山ノ内 路彦; 佐藤 英夫; 三浦 勝哉, 株式会社日立製作所, 国立大学法人東北大学
特願2011-119409, 27 May 2011
特開2012-248688, 13 Dec. 2012
特許第5492144号
07 Mar. 2014
201203057215523953

トンネル磁気抵抗効果素子及びそれを用いたランダムアクセスメモリ
Patent right, 山本 浩之; 高橋 宏昌; 伊藤 顕知; 早川 純; 山ノ内 路彦, 株式会社日立製作所
特願2011-518149, 08 Jun. 2009
特許第5456035号
17 Jan. 2014
201403091863078203

トンネル磁気抵抗効果素子及びそれを用いた磁気メモリセル並びに磁気ランダムアクセスメモリ
Patent right, 山ノ内 路彦; 黒崎 洋輔; 早川 純; 高橋 宏昌, 株式会社日立製作所
特願2012-515645, 20 May 2010
特許第5386637号
11 Oct. 2013
201403076782251700

トンネル磁気記録素子、磁気メモリセル及び磁気ランダムアクセスメモリ
Patent right, 早川 純; 山ノ内 路彦, 株式会社日立製作所
特願2011-502505, 06 Mar. 2009
特許第5166600号
28 Dec. 2012
201303076003569319

磁気メモリセル及び磁気ランダムアクセスメモリ
Patent right, 山ノ内 路彦; 高橋 宏昌; 早川 純, 株式会社日立製作所
特願2008-313679, 09 Dec. 2008
特開2010-140973, 24 Jun. 2010
特許第5075802号
31 Aug. 2012
201003056449612975

トンネル磁気抵抗効果素子及びそれを用いた磁気メモリセル並びに磁気ランダムアクセスメモリ
Patent right, 山ノ内 路彦; 黒崎 洋輔; 早川 純; 高橋 宏昌, 株式会社日立製作所
JP2010003397, 20 May 2010
WO2011-145146, 24 Nov. 2011
201303061404591190

トンネル磁気抵抗効果素子及びそれを用いたランダムアクセスメモリ
Patent right, 山本 浩之; 高橋 宏昌; 伊藤 顕知; 早川 純; 山ノ内 路彦, 株式会社日立製作所
JP2009060432, 08 Jun. 2009
WO2010-143248, 16 Dec. 2010
201203033722320430

トンネル磁気記録素子、磁気メモリセル及び磁気ランダムアクセスメモリ
Patent right, 早川 純; 山ノ内 路彦, 株式会社日立製作所
JP2009001017, 06 Mar. 2009
WO2010-100678, 10 Sep. 2010
201203095912507450