Researcher basic information

• 博士（工学）, 東北大学, Mar. 1995
• 工学修士, 東北大学, Mar. 1985

• https://researchmap.jp/read0075953?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200901040396602318
• https://www.ist.hokudai.ac.jp/
• https://www.ist.hokudai.ac.jp/eng/

• 200901040396602318

• Optically functional nanomaterial
• Spin-functional optical/photonic device
• Quantum-dot-based optical/photonic device
• Pico-second time-resolved photoluminescence scpectroscopy
• Semiconductor nanostructure
• Ultrafast spin dynamics
• Semiconductor quantum dot

• Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering), Electric and electronic materials, Semiconductor quantum dot, Optical device, Spin-functional optical device
• Nanotechnology/Materials, Optical engineering and photon science, Time-resolved photoluminescence spectroscopy, Spin dynamics
• Nanotechnology/Materials, Nanostructural physics, Semiconductor quantum dot, Optical device, Spin-functional optical device
• Nanotechnology/Materials, Crystal engineering, Semiconductor quantum dot

• 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

Research activity information

• Enhancement of Emission Efficiency and Color Tuning by Mixing Platinum(II) and Palladium(II) Complexes in a One‐dimensional Chain
  Kaito Segawa; Masaki Yoshida; Hiroto Kise; Junichi Takayama; Satoshi Hiura; Akihiro Murayama; Satoki Okabayashi; Motohiro Tsuboi; Takashi Tachikawa; Ken Onda; Masako Kato
  Angewandte Chemie International Edition, Wiley, 02 Sep. 2025, [Peer-reviewed]
  English, Scientific journal, Abstract
  
  A series of mixed metal crystals comprising square‐planar platinum(II) and palladium(II) complexes, K[M(CN)₂(dFppy)]·H₂O (M = Pt²⁺, Pd²⁺; dFppy = 2‐(4,6‐difluorophenyl)pyridinate), were prepared, and their unique luminescence properties—emerging upon mixing—were revealed. Seven mixed crystals with Pt/Pd ratios of 1:0.5, 1:1, 1:1.5, 1:2, 1:4.5, 1:10, and 1:13 adopt the same crystal structure (P2₁/c) as the pure metal complexes, in which the metal complexes are stacked with short M⋯M contacts (3.35–3.37 Å at 293 K). Reflecting the M⋯M interactions, the mixed crystals exhibited luminescence attributable to the emission from the triplet metal‐metal‐to‐ligand charge transfer (³MMLCT) state. The emission color varied with the Pt/Pd mixing ratio, and notably, a significant enhancement in emission quantum yield was observed (e.g., Φ = 0.64 for the Pt/Pd = 1:2 crystal at room temperature). The emission efficiency further improved at temperatures above room temperature. These unprecedented emission properties are explained by energy transfer among multiple emission sites within the one‐dimensional chain, involving excited oligomers containing various combinations of Pt and Pd complexes. Thus, metal mixing offers a new strategy for enhancing emission efficiency and enabling color tuning.
• Influence of bias voltage on the performance of polarization-sensitive near-infrared photodiode based on dilute nitride GaNAs
  Daiki Mineyama; Tatsuya Yano; Kohei Etou; Kaito Nakama; Hidetoshi Hashimoto; Keisuke Minehisa; Junichi Takayama; Agus Subagyo; Kazuhisa Sueoka; Fumitaro Ishikawa; Akihiro Murayama; Satoshi Hiura
  Applied Physics Letters, 126, 22, AIP Publishing, 02 Jun. 2025, [Peer-reviewed]
  English, Scientific journal, Recent advances in ultrafast light polarization modulation and electrical control of polarization have increased the demand for polarization-sensitive photodetectors to enable polarization-based optical communication systems. The conduction electron population of dilute nitride GaNAs changes with excitation light polarization owing to the spin-dependent recombination of conduction electrons via the dynamic polarization of defect electron spins. However, polarization-sensitive photodetectors that utilize this property are limited to photoconductive devices with a long response time. In this study, we developed a polarization-sensitive near-infrared photodiode based on GaNAs. The influence of light power and bias voltage on the discrimination efficiency between circularly and linearly polarized light was investigated using coupled rate equation analysis for polarization-dependent photocurrent characteristics. At −2.0 V, where the discrimination efficiency reached 1%, the extraction time of the conduction electrons to the electrode was estimated to be 34 ps. This result suggests that the developed polarization-sensitive photodiode can operate at 10 GHz. The discrimination efficiency increased with light power because of the activated spin-selective capture of conduction electrons by spin-polarized defect states for circularly polarized light, whereas it decreased with increasing reverse bias voltage. This low performance originates from suppressed spin-selective capture, which is due to the combination of electric-field-induced spin relaxation and a decrease in the capture efficiency of conduction electrons. This study provides valuable insights into the influence of the bias voltage on the polarization-dependent photocurrent, which is a key challenge to the realization of practical polarization-sensitive photodiodes based on the spin-dependent recombination effect of conduction electrons.
• Dynamics of Strongly Localized Excitons in GaAs/GaAsBi Core/Shell Nanowires
  Mattias Jansson; Satoshi Hiura; Junichi Takayama; Akihiro Murayama; Fumitaro Ishikawa; Weimin M. Chen; Irina A. Buyanova
  The Journal of Physical Chemistry C, 129, 9, 4456, 4463, American Chemical Society (ACS), 25 Feb. 2025, [Peer-reviewed]
  English, Scientific journal
• Efficient room-temperature spin-amplified luminescence of an InAs quantum dot tunnel coupled with a thin GaNAs spin filter
  Satoshi Hiura; Shino Sato; Shunsuke Sakano; Junichi Takayama; Akihiro Murayama
  Applied Physics Letters, 126, 5, AIP Publishing, 03 Feb. 2025, [Peer-reviewed]
  English, Scientific journal, Dilute nitride GaNAs has attracted much attention for spin generation owing to its defect-engineered spin filtering at room temperature. Strong, circularly polarized luminescence reflecting the spin-polarized electron states generated by a GaNAs spin filter is needed to realize practical opto-spintronics applications. This study examined the impacts of the GaNAs thickness on the room-temperature spin-polarized luminescence properties of tunnel-coupled InAs quantum dots (QDs) through polarization- and time-resolved photoluminescence in combination with a rate equation analysis. Reducing the GaNAs thickness from 20 to 5 nm increased the QD luminescence intensity by over an order of magnitude at low excitation powers. This increased luminescence was attributed to decreased electron capture in the deep-level defect states of GaNAs, which resulted from fewer defects in thinner GaNAs layers. Furthermore, the reduction in GaNAs thickness decreased the excitation power needed to maximize electron spin polarization of QDs while maintaining a near-maximum value. This efficient spin-amplified luminescence of QDs was achieved through spin-selective capture of QD electrons by defect states under low excitation spin densities. These results demonstrate that using a thin GaNAs spin filter can result in strong QD luminescence and high circular polarization at room temperature and low excitation spin densities. The findings give valuable implications for the development of spin-functional optical devices utilizing a GaNAs spin filter.
• Anti-reflective and luminescent GaAs/AlGaAs core–shell nanowires on Si wafer with 1 ns carrier lifetime up to 400 K
  Keisuke Minehisa; Hidetoshi Hashimoto; Kaito Nakama; Hiroto Kise; Shino Sato; Junichi Takayama; Satoshi Hiura; Akihiro Murayama; Fumitaro Ishikawa
  Journal of Applied Physics, 137, 3, AIP Publishing, 15 Jan. 2025, [Peer-reviewed]
  English, Scientific journal, We investigated the structural and optical properties of GaAs/Al0.8Ga0.2As core–shell nanowires (NWs) grown on a 2-in. Si wafer. The NWs exhibit low reflectance (<2%) across the visible to near-infrared range, attributed to their complex structure, intrinsic GaAs absorption, and a uniform NW density of approximately 3 × 108 cm−2 with an average length of 5 μm. Optical analyses based on Kubelka–Munk transformation and Tauc plot revealed minimal deviation between the estimated bandgap and the photoluminescence (PL) peak position. Temperature-dependent PL measurements between 300 and 400 K showed a weak intensity reduction and a characteristic temperature of 170 K, indicating stable emission properties within this range. Time-resolved-PL measurements demonstrated carrier lifetimes exceeding 1 ns up to 400 K, with a surface recombination velocity comparable to high-quality GaAs/AlGaAs NWs. These findings provide key insights into the optical performance and thermal stability of the NWs, highlighting their potential for optoelectronic devices operating at elevated temperatures.
• Room-temperature spin-conserved electron transport to semiconductor quantum dots using a superlattice barrier
  Satoshi Hiura; Saeko Hatakeyama; Mattias Jansson; Junichi Takayama; Irina Buyanova; Weimin Chen; Akihiro Murayama
  Physical Chemistry Chemical Physics, 27, 4, 2210, 2217, Royal Society of Chemistry (RSC), 2025, [Peer-reviewed]
  English, Scientific journal, We demonstrate an electron transport from superlattice barrier to quantum dots while keeping a high spin polarization at room temperature. This accomplishment is achieved by the electron transport being sufficiently faster than the spin relaxation.
• Thermo-responsive emission induced by different delocalized excited-states in isomorphous Pd(ii) and Pt(ii) one-dimensional chains
  Tomoya Saito; Masaki Yoshida; Kaito Segawa; Daisuke Saito; Junichi Takayama; Satoshi Hiura; Akihiro Murayama; Nishshanka M. Lakshan; W. M. C. Sameera; Atsushi Kobayashi; Masako Kato
  Chemical Science, 15, 35, 14497, 14505, Royal Society of Chemistry (RSC), 2024, [Peer-reviewed]
  English, Scientific journal, The emissions of isomorphous Pt(ii) and Pd(ii) one-dimensional chains exhibited distinct thermal responses, revealing the limiting factor for extending the excited-state delocalization across multiple molecules through metallophilic interactions.
• High-temperature efficient luminescence of dilute-nitride InGaAsN quantum dots with deep electron potential
  Ayano Morita; Satoshi Hiura; Junichi Takayama; Akihiro Murayama
  Journal of Applied Physics, 134, 22, AIP Publishing, 11 Dec. 2023, [Peer-reviewed]
  English, Scientific journal, The temperature dependence of the optical properties of In0.4Ga0.6As0.98N0.02 quantum dots (QDs) was investigated using continuous-wave and time-resolved photoluminescence (PL). Significant increases in the PL peak energy and the PL linewidth were observed at temperatures above 200 K, which reflected the high luminescence efficiency of ground and excited states at high temperatures. The PL decay times of the ground state were almost constant between 200 and 300 K at 200–220 ps, which were significantly longer than that of 38 ps for the In0.4Ga0.6As QDs at 300 K. The temperature independence of the PL decay time represents significant suppression of the thermal escape and the thermal excitation of electrons because the electron ground-state localization energy is much larger than the thermal energy. The PL intensity of the In0.4Ga0.6As0.98N0.02 QDs was seven times stronger than that of the In0.4Ga0.6As QDs at 300 K, and this tendency was maintained up to 400 K with a PL intensity one order of magnitude stronger. These findings demonstrate that lowering the QD conduction band by nitrogen incorporation is an effective approach for achieving strong QD luminescence above room temperature.
• Effect of dilute nitride GaNAs quantum well thickness on spin amplification dynamics of tunnel-coupled InAs quantum dots
  Shino Sato; Satoshi Hiura; Junichi Takayama; Akihiro Murayama
  Applied Physics Letters, 123, 23, AIP Publishing, 04 Dec. 2023, [Peer-reviewed]
  English, Scientific journal, Electron spin dynamics of dilute nitride GaNAs quantum well (QW)-InAs quantum dots (QDs) tunnel-coupled structures having different QW thicknesses were studied via circularly polarized time-resolved photoluminescence. The rate equation fitting considering a capture of QD electron spins by the GaNAs localized states via tunnel transfer revealed that the spin amplification dynamics of the QDs depended on the QW thickness. For the QW thickness of 5 nm, although the temporal amplification of QD electron spin polarization was slow owing to the weak wavefunction coupling between the QW and QD, the long duration of high electron spin polarization was observed because of the suppressed capture of QD majority spins relative to the efficient removal of QD minority spins. When the QW thickness increased from 5 to 20 nm, the strong spin filtering in GaNAs and strong wavefunction coupling led to the fast amplification of QD electron spin polarization with high initial spin polarization. However, the spin polarization rapidly decays after the amplification owing to the removal of both QD majority and minority spins, originating from many effective localized states. These results indicate that the time-dependent QD electron spin polarization and the resultant spin amplification can be widely tuned by changing the thickness of the tunnel-coupled GaNAs QW.
• Vapor‐Induced Assembly of a Platinum(II) Complex Loaded on Layered Double Hydroxide Nanoparticles
  Tamami Morimoto; Masaki Yoshida; Ayana Sato‐Tomita; Shunsuke Nozawa; Junichi Takayama; Satoshi Hiura; Akihiro Murayama; Atsushi Kobayashi; Masako Kato
  Chemistry – A European Journal, 29, 60, Wiley, 29 Sep. 2023, [Peer-reviewed]
  English, Scientific journal, Abstract
  
  Controlled self‐assembly of Pt^II complexes is key to the development of optical and stimuli‐responsive materials, but designing and precisely controlling them is still difficult owing to weak intermolecular interactions. Herein, we report the successful water‐vapor‐induced assembly of an anionic Pt^II complex [Pt(CN)₂(ppy)]⁻ (Hppy=2‐phenylpyridine) electrostatically loaded onto cationically charged layered double hydroxide (LDH) nanoparticles consisting of Mg²⁺ and Al³⁺ ions. When the Pt^II complexes were densely loaded onto the LDH nanoparticles, the assembly was maintained, even in dilute aqueous media. In the case of sparse loading, the Pt^II complexes were loaded discretely in the dry state; however, when water vapor was adsorbed, the increased mobility of the Pt^II complexes led to their assembly on the LDH nanoparticles. The presence of water vapor led to a drastic change in luminescence from green to orange.
• GaAs/GaInNAs core-multishell nanowires with a triple quantum-well structure emitting in the telecommunication range
  Kaito Nakama; Mitsuki Yukimune; Naohiko Kawasaki; Akio Higo; Satoshi Hiura; Akihiro Murayama; Mattias Jansson; Weimin M. Chen; Irina A. Buyanova; Fumitaro Ishikawa
  Applied Physics Letters, 123, 8, AIP Publishing, 21 Aug. 2023, [Peer-reviewed]
  English, Scientific journal, Semiconducting nanowires (NWs) fabricated from III–V materials have gained significant attention for their application in advanced optoelectronic devices. Here, the growth of GaAs/GaInNAs/GaAs core-multishell NWs with a triple quantum-well structure, having about 2% N and 20% In, is reported. The NWs are grown via selective area plasma-assisted molecular beam epitaxy on patterned Si(111) substrates with SiO2 mask holes. The nucleation and growth of the GaAs nanowires' core are carried out by Ga-induced vapor–liquid–solid growth at the open holes. Finely controlled, vertically aligned, regular core-multishell NWs with uniform wire length and diameter are obtained with a 96% yield and targeted nitrogen concentrations of 0%, 2%, and 3%. The GaInNAs NWs exhibit a spectral red shift relative to the GaAs NWs' peak. Their emission wavelength increases with the N content reaching up to 1.26 μm, which makes them a promising tool in telecommunication light sources.
• Electric-field driven source of photocarriers for tunable electron spin polarization in InGaAs quantum dots
  Hiroto Kise; Satoshi Hiura; Soyoung Park; Junichi Takayama; Kazuhisa Sueoka; Akihiro Murayama
  Applied Physics Letters, 122, 23, AIP Publishing, 05 Jun. 2023, [Peer-reviewed]
  English, Scientific journal, Electric-field control of spin polarization of electrons during injection into InGaAs quantum dots (QDs) was studied via circularly polarized time-resolved photoluminescence. Electric-field modulation of optical spin polarization in QDs will play a key role in future progress of semiconductor opto-spintronics. The tuning of band potentials by applying external electric fields can not only affect spin-injection efficiencies but also switch dominant spin-injection layers. In this study, we developed a QD-based electric-field-effect optical spin device with two different spin-injection layers, which consisted of a GaAs and GaAs/Al0.15Ga0.85As superlattice (SL) barriers. The bias-voltage modulation of the optical spin polarization in QDs was demonstrated by changing the spin polarization degree of electrons injected from these barriers into the QD via the electric-field switching of the spin-injection layers. This was achieved by exploiting the difference in spin relaxation properties between bulk GaAs and the SL. This proposed structure, which comprised of one luminescent layer and two spin-injection layers, is highly scalable because the modulation range of optical spin polarization can be enhanced by changing the combination of spin-injection layers, as well as the material used and its layer thickness.
• Efficient Room-Temperature Operation of a Quantum Dot Spin-Polarized Light-Emitting Diode under High-Bias Conditions
  Kohei Etou; Satoshi Hiura; Soyoung Park; Junichi Takayama; Agus Subagyo; Kazuhisa Sueoka; Akihiro Murayama
  Physical Review Applied, 19, 2, American Physical Society (APS), 21 Feb. 2023, [Peer-reviewed]
  English, Scientific journal
• Room-temperature electric field control of spin filtering efficiency for enhanced modulation of optical spin polarization in a defect-functional 0D–2D hybrid nanostructure
  Soyoung Park; Satoshi Hiura; Hiroto Kise; Junichi Takayama; Kazuhisa Sueoka; Akihiro Murayama
  Nanoscale, 15, 41, 16784, 16794, Royal Society of Chemistry (RSC), 2023, [Peer-reviewed]
  English, Scientific journal, We demonstrate an electric field control of optical spin polarization of InAs quantum dots in the range of 15–40% at room temperature. This accomplishment is achieved by tuning the spin amplification degree of dilute nitride GaNAs quantum well.
• Wafer-scale integration of GaAs/AlGaAs core–shell nanowires on silicon by the single process of self-catalyzed molecular beam epitaxy
  Keisuke Minehisa; Ryo Murakami; Hidetoshi Hashimoto; Kaito Nakama; Kenta Sakaguchi; Rikuo Tsutsumi; Takeru Tanigawa; Mitsuki Yukimune; Kazuki Nagashima; Takeshi Yanagida; Shino Sato; Satoshi Hiura; Akihiro Murayama; Fumitaro Ishikawa
  Nanoscale Advances, 5, 6, 1651, 1663, Royal Society of Chemistry (RSC), 2023, [Peer-reviewed]
  English, Scientific journal, Optically efficient GaAs/AlGaAs core–shell nanowires on 2-inch Si wafers before (front right) and after (others) growth. The samples show a dark-colored feature indicating light absorption on the substrate surface.
• Efficient Room‐Temperature Voltage Control of Picosecond Optical Spin Orientation Using a III‐V Semiconductor Nanostructure
  Soyoung Park; Satoshi Hiura; Junichi Takayama; Kazuhisa Sueoka; Akihiro Murayama
  Advanced Electronic Materials, 2200588, 2200588, Wiley, 15 Aug. 2022, [Peer-reviewed]
  English, Scientific journal
• Optical characterization and emission enhancement property of Ag nanomesh structure fabricated by nanosphere lithography
  Mai Ugajin; Soyoung Park; Takayuki Kiba; Junichi Takayama; Satoshi Hiura; Akihiro Murayama; Midori Kawamura; Yoshio Abe
  Surface and Coatings Technology, 435, 128258, 128258, Elsevier BV, Apr. 2022, [Peer-reviewed]
  English, Scientific journal
• Thermo‐ and Mechano‐Triggered Luminescence ON/OFF Switching by Supercooled Liquid/Crystal Transition of Platinum(II) Complex Thin Films
  Masaki Yoshida; Verner Sääsk; Daisuke Saito; Nobutaka Yoshimura; Junichi Takayama; Satoshi Hiura; Akihiro Murayama; Kaija Põhako‐Esko; Atsushi Kobayashi; Masako Kato
  Advanced Optical Materials, 10, 7, 2102614, 2102614, Wiley, Apr. 2022, [Peer-reviewed]
  English, Scientific journal
• Room-temperature spin transport properties in In0.5Ga0.5As quantum dot spin-polarized light-emitting diode
  Kohei Etou; Satoshi Hiura; Soyoung Park; Kazuya Sakamoto; Junichi Takayama; Agus Subagyo; Kazuhisa Sueoka; Akihiro Murayama
  Physical Review Applied, 16, 014034-1, 014034-10, Jul. 2021, [Peer-reviewed]
  English, 29996440;29996438
• Room-temperature electron spin polarization exceeding 90% in an opto-spintronic semiconductor nanostructure via remote spin filtering
  Yuqing Huang; Ville Polojärvi; Satoshi Hiura; Pontus Höjer; Arto Aho; Riku Isoaho; Teemu Hakkarainen; Mircea Guina; Shino Sato; Junichi Takayama; Akihiro Murayama; Irina A. Buyanova; Weimin M. Chen
  Nature Photonics, 15, 475, 482, Apr. 2021, [Peer-reviewed]
  English, Scientific journal, 29996440;29996438
• Electric-Field-Effect Spin Switching with an Enhanced Number of Highly Polarized Electron and Photon Spins Using p‑Doped Semiconductor Quantum Dots
  Soyoung Park; Hang Chen; Satoshi Hiura; Junichi Takayama; Kazuhisa Sueoka; Akihiro Murayama
  ACS Omega, 6, 8561, 8569, Mar. 2021, [Peer-reviewed], [Corresponding author]
  English, Scientific journal, 29996438;29996440
• Intense Red‐Blue Luminescence Based on Superfine Control of Metal–Metal Interactions for Self‐Assembled Platinum(II) Complexes
  Daisuke Saito; Tomohiro Ogawa; Masaki Yoshida; Junichi Takayama; Satoshi Hiura; Akihiro Murayama; Atsushi Kobayashi; Masako Kato
  Angewandte Chemie International Edition, 59, 42, 18723, 18730, Wiley, 12 Oct. 2020, [Peer-reviewed]
  Scientific journal
• Highly Efficient Room-Temperature Electron-Photon Spin Conversion Using a Semiconductor Hybrid Nanosystem with Gradual Quantum Dimensionality Reduction
  Satoshi Hiura; Mizuki Takishita; Junichi Takayama; Shino Sato; Akihiro Murayama
  Physical Review Applied, 14, 4, American Physical Society (APS), 08 Oct. 2020, [Peer-reviewed]
  Scientific journal
• Asymmetric spin relaxation induced by residual electron spin in semiconductor quantum-dot-superlattice hybrid nanosystem
  Satoshi Hiura; Saeko Hatakeyama; Junichi Takayama; Akihiro Murayama
  Applied Physics Letters, 116, 26, 262407, 262407, AIP Publishing, 29 Jun. 2020, [Peer-reviewed]
  Scientific journal
• Suppression of thermally excited electron-spin relaxation in InGaAs quantum dots using p-doped capping layers toward enhanced room-temperature spin polarization
  Shino Sato; Satoshi Hiura; Junichi Takayama; Akihiro Murayama
  Applied Physics Letters, 116, 18, 182401, 182401, AIP Publishing, 04 May 2020, [Peer-reviewed]
  Scientific journal
• Size dependence of emission enhancement of Tris(8-hydroxyquinolinato) aluminum with plasmonic Al nanostructure
  Natsumi Iijima; Mai Ugajin; Takayuki Kiba; Midori Kawamura; Yoshio Abe; Kyung Ho Kim; Akio Higo; Junichi Takayama; Satoshi Hiura; Akihiro Murayama
  Thin Solid Films, 700, 137920, 137920, Elsevier BV, Apr. 2020, [Peer-reviewed]
  Scientific journal
• Temperature dependence of inter-dot electron-spin transfer among laterally coupled excited states in high-density InGaAs quantum dots
  Shino Sato; Satoshi Hiura; Junichi Takayama; Akihiro Murayama
  Journal of Applied Physics, 127, 4, 043904, 043904, AIP Publishing, 31 Jan. 2020, [Peer-reviewed]
  Scientific journal
• Enhanced hetero-dimensional electron-spin injection in a resonantly tunnel-coupled InGaAs quantum dot–well nanosystem
  Hang Chen; Satoshi Hiura; Junichi Takayama; Soyoung Park; Kazuhisa Sueoka; Akihiro Murayama
  Applied Physics Express, 13, 1, 015003, 015003, IOP Publishing, 01 Jan. 2020, [Peer-reviewed]
  Scientific journal
• New Optical Functionalities Developed by Using Semiconductor Quantum-dot Crystals
  Akihiro MURAYAMA
  電子情報通信学会誌, 102, 10, 938, 941, Oct. 2019, [Peer-reviewed], [Invited], [Lead author, Corresponding author]
  Japanese, Scientific journal
• Photoluminescence of InGaAs/GaAs Quantum Nanodisk in Pillar Fabricated by Biotemplate, Dry Etching, and MOVPE Regrowth
  Akio Higo; Takayuki Kiba; Junichi Takayama; Chang Yong Lee; Cedric Thomas; Takuya Ozaki; Hassanet Sodabanlu; Masakazu Sugiyama; Yoshiaki Nakano; Ichiro Yamashita; Akihiro Murayama; Seiji Samukawa
  ACS Applied Electronic Materials, 1, 9, 1945, 1951, American Chemical Society (ACS), 24 Sep. 2019, [Peer-reviewed]
  Scientific journal
• Layer-selective spin amplification in size-modulated quantum nanocolumn
  Satoshi Hiura; Shotaro Saito; Junichi Takayama; Takayuki Kiba; Akihiro Murayama
  Applied Physics Letters, 115, 1, 013102, 013102, AIP Publishing, Jul. 2019, [Peer-reviewed]
  Scientific journal
• Emission enhancement of tris(8-quinolinolato)aluminum with Al nanotriangle arrays fabricated by nanosphere lithography
  Takayuki Kiba; Natsumi Iijima; Kazuki Yanome; Midori Kawamura; Yoshio Abe; Kyung Ho Kim; Mai Takase; Akio Higo; Junichi Takayama; Satoshi Hiura; Akihiro Murayama
  Applied Surface Science, 478, 49, 53, Elsevier BV, Jun. 2019, [Peer-reviewed]
  Scientific journal
• Electron-transfer-induced metallic electronic states in a H/Fe3O4(001) film subsurface
  Satoshi Hiura; Agus Subagyo; Akihiro Murayama; Kazuhisa Sueoka
  Applied Physics Express, 12, 5, 055502, 055502, IOP Publishing, 01 May 2019, [Peer-reviewed]
  Scientific journal
• Electric field control of spin polarity in spin injection into InGaAs quantum dots from a tunnel-coupled quantum well
  Hang Chen; Satoshi Hiura; Junichi Takayama; Soyoung Park; Kazuhisa Sueoka; Akihiro Murayama
  Applied Physics Letters, 114, 13, 133101, 133101, AIP Publishing, Apr. 2019, [Peer-reviewed]
  Scientific journal
• Quantum spin transport to semiconductor quantum dots through superlattice
  Satoshi Hiura; Kodai Itabashi; Kazuki Takeishi; Junichi Takayama; Takayuki Kiba; Akihiro Murayama
  Applied Physics Letters, 114, 7, 072406, 072406, AIP Publishing, 18 Feb. 2019, [Peer-reviewed]
  Scientific journal
• Interdot carrier and spin dynamics in a two-dimensional high-density quantum-dot array of InGaAs with quantum dots embedded as local potential minima
  Satoshi Hiura; Masayuki Urabe; Kazuki Takeishi; Kodai Itabashi; Junichi Takayama; Takayuki Kiba; Kazuhisa Sueoka; Akihiro Murayama
  Semiconductor Science and Technology, 34, 2, 025001, 025001, IOP Publishing, 01 Feb. 2019, [Peer-reviewed]
  Scientific journal
• Temperature dependence of the radiative recombination time in laterally coupled GaAs quantum dots
  Heedae Kim; Akihiro Murayama; Jongsu Kim; Jindong Song
  Applied Surface Science, 457, 497, 500, Elsevier BV, Nov. 2018, [Peer-reviewed]
  Scientific journal
• Persistent High Polarization of Excited Spin Ensembles During Light Emission in Semiconductor Quantum-Dot-Well Hybrid Nanosystems
  Kazuki Takeishi; Satoshi Hiura; Junichi Takayama; Kodai Itabashi; Masayuki Urabe; Akihiro Washida; Takayuki Kiba; Akihiro Murayama
  Physical Review Applied, 10, 3, American Physical Society (APS), 10 Sep. 2018, [Peer-reviewed]
  Scientific journal
• Carrier Relaxation Dynamics Between Localized Vertical Confinement States in GaAs/AlGaAs Quantum Rings
  Seongho Park; Jongsu Kim; Junich Takayama; Akihiro Murayama; Kwangseuk Kyhm
  Journal of the Korean Physical Society, 73, 3, 314, 319, Korean Physical Society, Aug. 2018, [Peer-reviewed]
  Scientific journal
• Photoluminescence enhancement of tris(8-hydroxyquinolinato)aluminum thin film by plasmonic Ag nanotriangle array fabricated by nanosphere lithography
  Kazuki Yanome; Takayuki Kiba; Kazuaki Masui; Midori Kawamura; Yoshio Abe; Kyung Ho Kim; Mai Takase; Junichi Takayama; Akihiro Murayama
  Thin Solid Films, 660, 907, 912, Elsevier BV, Aug. 2018, [Peer-reviewed]
  Scientific journal
• Time-resolved photoluminescence study of tris(8-hydroxyquinolinato) aluminium with surface plasmon resonance of Ag nanoparticles
  Kazuaki Masui; Takayuki Kiba; Aoto Sato; Kazuki Yanome; Midori Kawamura; Yoshio Abe; Kyung Ho Kim; Hee Dae Kim; Junichi Takayama; Akihiro Murayama
  Thin Solid Films, 660, 938, 943, Elsevier BV, Aug. 2018, [Peer-reviewed]
  Scientific journal
• Interdot spin transfer dynamics in laterally coupled excited spin ensemble of high-density InGaAs quantum dots
  Satoshi Hiura; Kazuki Takeishi; Masayuki Urabe; Kodai Itabashi; Junichi Takayama; Takayuki Kiba; Kazuhisa Sueoka; Akihiro Murayama
  Applied Physics Letters, 113, 2, 023104, 023104, AIP Publishing, 09 Jul. 2018, [Peer-reviewed]
  Scientific journal
• Magnetic field insensitive photoluminescence decay of ZnSe/CdS core/shell type-II colloidal quantum dots
  Woojin Lee; Seongho Park; Akihiro Murayama; Jong-soo Lee; Kwangseuk Kyhm
  Japanese Journal of Applied Physics, 57, 6S1, 06HE06, 06HE06, IOP Publishing, 01 Jun. 2018, [Peer-reviewed]
  Scientific journal
• Temperature-dependent radiative and non-radiative dynamics of photo-excited carriers in extremely high-density and small InGaN nanodisks fabricated by neutral-beam etching using bio-nano-templates
  Yafeng Chen; Takayuki Kiba; Junichi Takayama; Akio Higo; Tomoyuki Tanikawa; Shula Chen; Seiji Samukawa; Akihiro Murayama
  Journal of Applied Physics, 123, 20, 204305, 204305, AIP Publishing, 28 May 2018, [Peer-reviewed]
  Scientific journal
• Growth of Semiconductor Self-assembled Quantum Dots by Molecular Beam Epitaxy and the Dynamics of Photo-excited Carriers
  Akihiro MURAYAMA; Junichi TAKAYAMA; Satoshi HIURA; Takayuki KIBA
  Vacuum and Surface Science, 61, 5, 315, 324, Surface Science Society Japan, 10 May 2018, [Peer-reviewed], [Invited], [Lead author, Corresponding author]
  Japanese, Scientific journal
• Effect of a Phonon Bottleneck on Exciton and Spin Generation in Self-Assembled In1−xGaxAs Quantum Dots
  Y. Q. Huang; I. A. Buyanova; X. J. Yang; A. Murayama; W. M. Chen
  Physical Review Applied, 9, 4, American Physical Society (APS), 26 Apr. 2018, [Peer-reviewed]
  Scientific journal
• Optical Study of Sub-10 nm In0.3Ga0.7N Quantum Nanodisks in GaN Nanopillars
  Akio Higo; Takayuki Kiba; Shula Chen; Yafeng Chen; Tomoyuki Tanikawa; Cedric Thomas; Chang Yong Lee; Yi-Chun Lai; Takuya Ozaki; Junichi Takayama; Ichiro Yamashita; Akihiro Murayama; Seiji Samukawa
  ACS Photonics, 4, 7, 1851, 1857, American Chemical Society (ACS), 19 Jul. 2017, [Peer-reviewed]
  Scientific journal
• Spectroscopic and Photoluminescent Properties of Indium Zinc Oxide (IZO) and IZO/Ag/IZO Sandwiched Film
  Kazuki Yanome; Takayuki Kiba; Midori Kawamura; Yoshio Abe; Kyung Ho Kim; Junichi Takayama; Akihiro Murayama
  Journal of Electronic Materials, 46, 7, 3873, 3879, Springer Science and Business Media LLC, Jul. 2017, [Peer-reviewed]
  Scientific journal
• Direct observation of subsurface charge ordering in Fe3O4(001) by scanning tunneling microscopy/spectroscopy
  Satoshi Hiura; Akira Ikeuchi; Masafumi Jochi; Riku Yamazaki; Sotaro Takahashi; Agus Subagyo; Akihiro Murayama; Kazuhisa Sueoka
  Applied Physics Express, 10, 4, 045701, 045701, IOP Publishing, 01 Apr. 2017, [Peer-reviewed]
  Scientific journal
• Emission enhancement in indium zinc oxide(IZO)/Ag/IZO sandwiched structure due to surface plasmon resonance of thin Ag film
  Takayuki Kiba; Kazuki Yanome; Midori Kawamura; Yoshio Abe; Kyung Ho Kim; Junichi Takayama; Akihiro Murayama
  Applied Surface Science, 389, 906, 910, Elsevier BV, Dec. 2016, [Peer-reviewed]
  Scientific journal
• Nanometer scale fabrication and optical response of InGaN/GaN quantum disks
  Yi-Chun Lai; Akio Higo; Takayuki Kiba; Cedric Thomas; Shula Chen; Chang Yong Lee; Tomoyuki Tanikawa; Shigeyuki Kuboya; Ryuji Katayama; Kanako Shojiki; Junichi Takayama; Ichiro Yamashita; Akihiro Murayama; Gou-Chung Chi; Peichen Yu; Seiji Samukawa
  Nanotechnology, 27, 42, 425401, 425401, IOP Publishing, 21 Oct. 2016, [Peer-reviewed]
  Scientific journal
• Temperature-Dependent Operation of GaAs Quantum Nanodisk LEDs with Asymmetric AlGaAs Barriers
  Yosuke Tamura; Akio Higo; Takayuki Kiba; Cedric Thomas; Junichi Takayama; Ichiro Yamashita; Akihiro Murayama; Seiji Samukawa
  IEEE Transactions on Nanotechnology, 15, 3, 557, 562, Institute of Electrical and Electronics Engineers (IEEE), May 2016, [Peer-reviewed]
  Scientific journal
• Power-dependent spin amplification in (In, Ga)As/GaAs quantum well via Pauli blocking by tunnel-coupled quantum dot ensembles
  S. L. Chen; T. Kiba; X. J. Yang; J. Takayama; A. Murayama
  Applied Physics Letters, 108, 15, 152103, 152103, AIP Publishing, 11 Apr. 2016, [Peer-reviewed]
  Scientific journal
• Temperature-dependent spin injection dynamics in InGaAs/GaAs quantum well-dot tunnel-coupled nanostructures
  S. L. Chen; T. Kiba; X. J. Yang; J. Takayama; A. Murayama
  Journal of Applied Physics, 119, 11, 115701, 115701, AIP Publishing, 21 Mar. 2016, [Peer-reviewed]
  Scientific journal
• Tuning of the electrongfactor in defect-free GaAs nanodisks
  Li-Wei Yang; Yi-Chia Tsai; Yiming Li; Aiko Higo; Akihiro Murayama; S. Samukawa; O. Voskoboynikov
  Physical Review B, 92, 24, American Physical Society (APS), 15 Dec. 2015, [Peer-reviewed]
  Scientific journal
• Electron g-factor and spin decoherence in GaAs quantum nanodisks fabricated by fully top-down lithography
  Toru Tanaka; Takayuki Kiba; Akio Higo; Cedric Thomas; Yosuke Tamura; Seiji Samukawa; Akihiro Murayama
  Journal of Crystal Growth, 425, 295, 298, Elsevier BV, Sep. 2015, [Peer-reviewed]
  Scientific journal
• Time-resolved measurements of Cooper-pair radiative recombination in InAs quantum dots
  S. S. Mou
  Journal of Applied Physics, 118, 7, 073102, 073102, AIP Publishing, 21 Aug. 2015, [Peer-reviewed]
  Scientific journal
• Light-Emitting Devices Based on Top-down Fabricated GaAs Quantum Nanodisks
  Akio Higo; Takayuki Kiba; Yosuke Tamura; Cedric Thomas; Junichi Takayama; Yunpeng Wang; Hassanet Sodabanlu; Masakazu Sugiyama; Yoshiaki Nakano; Ichiro Yamashita; Akihiro Murayama; Seiji Samukawa
  Scientific Reports, 5, 1, Springer Science and Business Media LLC, Aug. 2015, [Peer-reviewed]
  Scientific journal
• Optical observation of superconducting density of states in luminescence spectra of InAs quantum dots
  S. S. Mou; H. Irie; Y. Asano; K. Akahane; H. Nakajima; H. Kumano; M. Sasaki; A. Murayama; I. Suemune
  Physical Review B, 92, 3, American Physical Society (APS), 27 Jul. 2015, [Peer-reviewed]
  Scientific journal
• Polarization anisotropy of exciton in self-assembled elliptical InP/InGaP quantum dots
  Inhong Kim; Takayuki Kiba; Akihiro Murayama; Jin Dong Song; Kwangseuk Kyhm
  Current Applied Physics, 15, 6, 733, 738, Elsevier BV, Jun. 2015, [Peer-reviewed]
  Scientific journal
• Size dependence of electron spin dephasing in InGaAs quantum dots
  Y. Q. Huang; Y. Puttisong; I. A. Buyanova; X. J. Yang; A. Subagyo; K. Sueoka; A. Murayama; W. M. Chen
  Applied Physics Letters, 106, 9, 093109, 093109, AIP Publishing, 02 Mar. 2015, [Peer-reviewed]
  Scientific journal
• Impact of artificial lateral quantum confinement on exciton-spin relaxation in a two-dimensional GaAs electronic system
  Takayuki Kiba; Toru Tanaka; Yosuke Tamura; Akio Higo; Cedric Thomas; Seiji Samukawa; Akihiro Murayama
  AIP Advances, 4, 10, 107112, 107112, AIP Publishing, Oct. 2014, [Peer-reviewed]
  Scientific journal
• Anomalous spectral dependence of optical polarization and its impact on spin detection in InGaAs/GaAs quantum dots
  Y. Puttisong; Y. Q. Huang; I. A. Buyanova; X. J. Yang; A. Subagyo; K. Sueoka; A. Murayama; W. M. Chen
  Applied Physics Letters, 105, 13, 132106, 132106, AIP Publishing, 29 Sep. 2014, [Peer-reviewed]
  Scientific journal
• Growth-temperature dependence of optical spin-injection dynamics in self-assembled InGaAs quantum dots
  Takafumi Yamamura; Takayuki Kiba; Xiaojie Yang; Junichi Takayama; Agus Subagyo; Kazuhisa Sueoka; Akihiro Murayama
  Journal of Applied Physics, 116, 9, 094309, 094309, AIP Publishing, 07 Sep. 2014, [Peer-reviewed]
  Scientific journal
• Temperature dependence of the radiative recombination time in ZnO nanorods under an external magnetic field of 6T
  W. Lee; T. Kiba; A. Murayama; C. Sartel; V. Sallet; I. Kim; R. A. Taylor; Y. D. Jho; K. Kyhm
  Optics Express, 22, 15, 17959, 17959, The Optical Society, 28 Jul. 2014, [Peer-reviewed]
  Scientific journal
• Photophysical Properties and Biocompatibility of Photoluminescent Y2O3:Eu Nanoparticles in Polymethylmetacrylate Matrix
  Shigeaki Abe; Yusuke Hamba; Nobuki Iwadera; Shuichi Yamagata; Yasutaka Yawaka; Motohiro Uo; Junichiro Iida; Takayuki Kiba; Akihiro Murayama; Fumio Watari
  Journal of Nanoscience and Nanotechnology, 14, 4, 2891, 2894, American Scientific Publishers, 01 Apr. 2014, [Peer-reviewed]
  Scientific journal
• Ultrafast spin tunneling and injection in coupled nanostructures of InGaAs quantum dots and quantum well
  Xiao-Jie Yang; Takayuki Kiba; Takafumi Yamamura; Junichi Takayama; Agus Subagyo; Kazuhisa Sueoka; Akihiro Murayama
  Applied Physics Letters, 104, 1, 012406, 012406, AIP Publishing, 06 Jan. 2014, [Peer-reviewed]
  Scientific journal
• Preparation and biocompatibilities of luminescent europium-doped yttria and titania nanoparticles
  Shigeaki ABE; Yusuke HAMBA; Atsushi HYONO; Shuichi YAMAGATA; Motohiro UO; Junichiro IIDA; Takayuki KIBA; Akihiro MURAYAMA; Tsukasa AKASAKA; Fumio WATARI
  Journal of the Ceramic Society of Japan, 122, 1423, 216, 221, Ceramic Society of Japan, 2014, [Peer-reviewed]
  Scientific journal
• Temperature dependence of time-resolved photoluminescence in closely packed alignment of Si nanodisks with SiC barriers
  Takayuki Kiba; Yoshiya Mizushima; Makoto Igarashi; Chi-Hsien Huang; Seiji Samukawa; Akihiro Murayama
  Nanoscale Research Letters, 8, 1, Springer Science and Business Media LLC, Dec. 2013, [Peer-reviewed]
  Scientific journal
• Surface/interface-related optical properties in Si nanodisks fabricated by neutral-beam etching using bio-templates
  Takayuki Kiba; Kenta Suzaki; Hao Li; Makoto Igarashi; Seiji Samukawa; Akihiro Murayama
  Journal of Crystal Growth, 378, 493, 496, Elsevier BV, Sep. 2013, [Peer-reviewed]
  Scientific journal
• Dynamics of electron-spin injection in a heterovalent GaAs/AlGaAs/ZnMnSe structure with a coupled double quantum well of GaAs/AlGaAs
  Y. Kuno; T. Sasaki; T. Kiba; V.Kh. Kaibyshev; F. Liaci; A.A. Toropov; S.V. Ivanov; A. Murayama
  Journal of Crystal Growth, 378, 393, 396, Elsevier BV, Sep. 2013, [Peer-reviewed]
  Scientific journal
• Temperature dependence of the dynamics of optical spin injection in self-assembled InGaAs quantum dots
  Takayuki Kiba; Xiao-jie Yang; Takafumi Yamamura; Yuki Kuno; Agus Subagyo; Kazuhisa Sueoka; Akihiro Murayama
  Applied Physics Letters, 103, 8, 082405, 082405, AIP Publishing, 19 Aug. 2013, [Peer-reviewed]
  Scientific journal
• Quantum size effects in GaAs nanodisks fabricated using a combination of the bio-template technique and neutral beam etching
  Yosuke Tamura; Toshiyuki Kaizu; Takayuki Kiba; Makoto Igarashi; Rikako Tsukamoto; Akio Higo; Weiguo Hu; Cedric Thomas; Mohd Erman Fauzi; Takuya Hoshii; Ichiro Yamashita; Yoshitaka Okada; Akihiro Murayama; Seiji Samukawa
  Nanotechnology, 24, 28, 285301, 285301, IOP Publishing, 19 Jul. 2013, [Peer-reviewed]
  Scientific journal
• Photophysical Properties of Self-assembled Cyanine-dye Dimmer Formation Assisted by Cyclodextrin Inclusion Complexation
  Shigeaki Abe; Takashi Hirota; Takayuki Kiba; Naoyuki Miyakawa; Fumio Watari; Akihiro Murayama; Shin-Ichiro Sato
  Molecular Crystals and Liquid Crystals, 579, 1, 22, 29, Informa UK Limited, Jan. 2013, [Peer-reviewed]
  Scientific journal
• Structure and Intermolecular Dynamics of Carbon Disulfide/Alcohols Binary Solution
  Takayuki Kiba; Takashi Hirota; Akihiro Murayama; Shin-Ichiro Sato
  Molecular Crystals and Liquid Crystals, 579, 1, 103, 109, Informa UK Limited, Jan. 2013, [Peer-reviewed]
  Scientific journal
• High-density optical spin injection in self-assembled semiconductor quantum dots
  Akihiro Murayama; Norihiro Tamura; Tatsushiro Yamazaki; Takayuki Kiba
  Journal of Luminescence, 133, 110, 113, Elsevier BV, Jan. 2013, [Peer-reviewed]
  Scientific journal
• Spectral Narrowing of UV-Visible Absorption and Emission Spectra of Anthracene-Derivatives in β-Cyclodextrin Nanocavity: Effects of Host/Guest Stoichiometry
  Shin-Ichiro Sato; Yuuki Yoshizumi; Takayuki Kiba; Akihiro Murayama; Shigeaki Abe
  Molecular Crystals and Liquid Crystals, 568, 1, 60, 65, Informa UK Limited, 03 Dec. 2012, [Peer-reviewed]
  Scientific journal
• Picosecond carrier dynamics induced by coupling of wavefunctions in a Si-nanodisk array fabricated by neutral beam etching using bio-nano-templates
  Takayuki Kiba; Yoshiya Mizushima; Makoto Igarashi; Seiji Samukawa; Akihiro Murayama
  Nanoscale Research Letters, 7, 1, Springer Science and Business Media LLC, Dec. 2012, [Peer-reviewed]
  Scientific journal
• Antiferromagnetic interaction in coupled CdSe/ZnMnSe quantum dot structures
  D. Dagnelund; Q. J. Ren; I. A. Buyanova; A. Murayama; W. M. Chen
  Applied Physics Letters, 101, 5, 052405, 052405, AIP Publishing, 30 Jul. 2012, [Peer-reviewed]
  Scientific journal
• Sub-Picosecond Spin Relaxation of Bright Excitons and Imbalance Suppression in Asymmetric Cdse/Zns Nanocrystal Quantum Dots Under an Applied Magnetic Field
  Kwangseuk Kyhm; Jihoon Kim; Ho-Soon Yang; Koo-Chul Je; Akihiro Murayama
  Journal of Nanoscience and Nanotechnology, 12, 3, 2919, 2923, American Scientific Publishers, 01 Mar. 2012, [Peer-reviewed]
  Scientific journal
• Control of optical bandgap energy and optical absorption coefficient by geometric parameters in sub-10 nm silicon-nanodisc array structure
  Mohd Fairuz Budiman; Weiguo Hu; Makoto Igarashi; Rikako Tsukamoto; Taiga Isoda; Kohei M Itoh; Ichiro Yamashita; Akihiro Murayama; Yoshitaka Okada; Seiji Samukawa
  Nanotechnology, 23, 6, 065302, 065302, IOP Publishing, 17 Feb. 2012, [Peer-reviewed]
  Scientific journal
• Picosecond transient photoluminescence in high-density Si-nanodisk arrays fabricated using bio-nano-templates
  Takayuki Kiba; Yoshiya Mizushima; Makoto Igarashi; Chi-Hsien Huang; Seiji Samukawa; Akihiro Murayama
  Applied Physics Letters, 100, 5, 053117, 053117, AIP Publishing, 30 Jan. 2012, [Peer-reviewed]
  Scientific journal
• Plasmonic enhancements of photoluminescence in hybrid Si nanostructures with Au fabricated by fully top-down lithography
  Koudo Nakaji; Hao Li; Takayuki Kiba; Makoto Igarashi; Seiji Samukawa; Akihiro Murayama
  Nanoscale Research Letters, 7, 1, 629, 629, Springer Science and Business Media LLC, 2012, [Peer-reviewed]
  Scientific journal
• Optical absorption characteristic of highly ordered and dense two-dimensional array of silicon nanodiscs
  Chi-Hsien Huang; Xuan-Yu Wang; Makoto Igarashi; Akihiro Murayama; Yoshitaka Okada; Ichiro Yamashita; Seiji Samukawa
  Nanotechnology, 22, 10, 105301, 105301, IOP Publishing, 11 Mar. 2011, [Peer-reviewed]
  Scientific journal
• Remote plasma chemical vapor deposition of carbon nanotubes and analysis of plasma effect
  Y. Fukuda; J. Takayama; N. Asaoka; Y. Suda; H. Sugawara; A. Murayama
  IEEE Transactions on Plasma Science, 39, 3133, 3139, 2011, [Peer-reviewed]
• Defect-free etching process for GaAs/AlGaAs hetero-nanostructure using chlorine/argon mixed neutral beam
  Xuan-Yu Wang; Chi-Hsien Huang; Yuzo Ohno; Mokoto Igarashi; Akihiro Murayama; Seiji Samukawa
  Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena, 28, 6, 1138, 1142, American Vacuum Society, Nov. 2010, [Peer-reviewed]
  Scientific journal
• Spin Dynamics in ZnO-Based Materials
  I. A. Buyanova; A. Murayama; T. Furuta; Y. Oka; D. P. Norton; S. J. Pearton; A. Osinsky; J. W. Dong; C. W. Tu; W. M. Chen
  Journal of Superconductivity and Novel Magnetism, 23, 1, 161, 165, Springer Science and Business Media LLC, Jan. 2010, [Peer-reviewed]
  Scientific journal
• Transfer dynamics of spin-polarized excitons into semiconductor quantum dots
  A. Murayama; T. Furuta; S. Oshino; K. Hyomi; M. Sakuma; I. Souma; D. Dagnelund; I.A. Buyanova; W.M. Chen
  Journal of Luminescence, 129, 12, 1927, 1930, Elsevier BV, Dec. 2009, [Peer-reviewed]
  Scientific journal
• Micro-photoluminescence study of electron-spin injection in self-assembled semiconductor quantum dots
  K. Hyomi; M. Sakuma; A. Murayama
  Journal of Luminescence, 129, 12, 1715, 1717, Elsevier BV, Dec. 2009, [Peer-reviewed]
  Scientific journal
• SPIN DYNAMICS IN III-V/II-VI: Mn HETEROVALENT QUANTUM WELLS
  A. A. TOROPOV; YA. V. TERENT'EV; A. V. LEBEDEV; P. S. KOP'EV; S. V. IVANOV; T. KOYAMA; K. NISHIBAYASHI; A. MURAYAMA; Y. OKA
  International Journal of Modern Physics B, 23, 12n13, 2739, 2749, World Scientific Pub Co Pte Lt, 20 May 2009, [Peer-reviewed]
  Scientific journal, We report on the spectroscopic magnetooptical studies of spin dynamics in diluted magnetic semiconductor (DMS) GaAs / AlGaAs / ZnSe / ZnCdMnSe heterovalent double quantum wells (QW). The transients of circularly polarized photoluminescence in an external magnetic field are detected in the structures with different widths of the GaAs QW. The analysis of the data, performed within the rate-equation model, has allowed separate estimations of the spin relaxation rate of localized electrons and holes. The spin flip of the electrons confined in the DMS ZnCdMnSe QW is faster than 20 ps, whereas the spin flip of the heavy hole localized in the GaAs QW is as long as ~9 ns. The long spin flip of the holes is presumably governed by their strong 3-dimensional localization.
• Magnetic field induced charging effect in a single CdSe quantum dot
  Qijun Ren; Lihui Bai; Akihiro Murayama; Zhanghai Chen; Xuechu Shen
  physica status solidi (b), 246, 4, 791, 794, Wiley, Apr. 2009, [Peer-reviewed]
  Scientific journal
• Exciton broadening and spin dynamics in III-V/II-VI:Mn heterovalent double quantum wells
  A. A. Toropov; Ya. V. Terent’ev; P. S. Kop’ev; S. V. Ivanov; T. Koyama; K. Nishibayashi; A. Murayama; Y. Oka; A. Golnik; J. A. Gaj
  Physical Review B, 77, 23, American Physical Society (APS), 13 Jun. 2008, [Peer-reviewed]
  Scientific journal
• Spin-Conserving Tunneling of Excitons in Diluted Magnetic Semiconductor Double Quantum Wells
  Jiho Park; Akihiro Murayama; Izuru Souma; Yasuo Oka; Daniel Dangnelund; Irina A. Buyanova; Weimin Chen
  Japanese Journal of Applied Physics, 47, 5, 3533, 3536, IOP Publishing, 16 May 2008, [Peer-reviewed]
  Scientific journal
• Spin injection in a coupled system of a diluted magnetic semiconductor Zn0.80Mn0.20Se and self-assembled quantum dots of CdSe
  D. Dagnelund; I.A. Buyanova; W.M. Chen; A. Murayama; T. Furuta; K. Hyomi; I. Souma; Y. Oka
  Superlattices and Microstructures, 43, 5-6, 615, 619, Elsevier BV, May 2008, [Peer-reviewed]
  Scientific journal
• Dominant factors limiting efficiency of optical spin detection in ZnO-based materials
  W. M. Chen; I. A. Buyanova; A. Murayama; T. Furuta; Y. Oka; D. P. Norton; S. J. Pearton; A. Osinsky; J. W. Dong
  Applied Physics Letters, 92, 9, 092103, 092103, AIP Publishing, 03 Mar. 2008, [Peer-reviewed]
  Scientific journal
• Magneto-optical and tunable laser excitation spectroscopy of spin-injection and spin loss from Zn(Cd)MnSe diluted magnetic quantum well to CdSe non-magnetic quantum dots
  D. Dagnelund; I.A. Buyanova; W.M. Chen; A. Murayama; T. Furuta; K. Hyomi; I. Souma; Y. Oka
  Materials Science and Engineering: B, 147, 2-3, 262, 266, Elsevier BV, Feb. 2008, [Peer-reviewed]
  Scientific journal
• Efficiency of optical spin injection and spin loss from a diluted magnetic semiconductor ZnMnSe to CdSe nonmagnetic quantum dots
  D. Dagnelund; I. A Buyanova; W. M. Chen; A. Murayama; T. Furuta; K. Hyomi; I. Souma; Y. Oka
  Physical Review B, 77, 3, American Physical Society (APS), 31 Jan. 2008, [Peer-reviewed]
  Scientific journal
• Magneto-photoluminescence from single quantum structures of diluted magnetic semiconductor fabricated by e-beam lithography
  A. Murayama; H. Hirano; K. Hyomi; M. Sakuma; I. Souma; Y. Oka
  Journal of Luminescence, 122-123, 834, 837, 2007, [Peer-reviewed], [Lead author]
• Dynamics of exciton-spin injection, transfer, and relaxation in self-assembled quantum dots of CdSe coupled with a diluted magnetic semiconductor layer of Zn0.80Mn0.20Se
  A. Murayama; T. Furuta; K. Hyomi; I. Souma; Y. Oka; D. Dagnelund; I.A. Buyanova; W.M. Chen
  Physical Review B, 75, 195308, 2007, [Peer-reviewed], [Lead author]
• Spin-resolved magneto-optical study of CdSe single quantum dot
  Z.H. Chen; L.H. Bai; S.H. Huang; H. Xiong; S.C. Shen; I. Souma; K. Hyomi; A. Murayama; Y. Oka
  International Journal of Modern Physics B, 21, 1549, 1554, 2007, [Peer-reviewed]
• Direct observation of relaxation dynamics of spin-polarized electrons excited at a higher-energy spin-split subband in a diluted magnetic semiconductor quantum well
  K. Saito; J.H. Park; I. Souma; Y. Oka; A. Murayama
  Applied Physics Letters, 90, 262111, 2007, [Peer-reviewed], [Corresponding author]
• Phonon-induced efficient transfer of spin-polarized excitons in diluted magnetic semiconductor double quantum wells
  J.H. Park; K. Saito; I. Souma; Y. Oka; A. Murayama
  Japanese Journal of Applied Physics, 46, 7290, 7293, 2007, [Peer-reviewed], [Corresponding author]
• Ultrafast spin injection from Cd1-xMnxTe magnetic barriers into a CdTe quantum well studied by pump-probe spectroscopy
  I. Aoshima; K. Nishibayashi; I. Souma; A. Murayama; Y. Oka
  Journal of Luminescence, 119-120, 437, 441, 2006, [Peer-reviewed], [Corresponding author]
• Pump-probe spectroscopy of spin-injection dynamics in double quantum wells of diluted magnetic semiconductor
  K. Nishibayashi; I. Aoshima; I. Souma; A. Murayama; Y. Oka
  Journal of Luminescence, 119-120, 433, 436, 2006, [Peer-reviewed]
• Magneto-optical properties in hybrid nanostructures of II-VI diluted magnetic semiconductors with perpendicular ferromagnetic films
  M. Sakuma; K. Hyomi; I. Souma; A. Murayama; Y. Oka
  Physica Status Solidi (b), 243, 902, 905, 2006, [Peer-reviewed], [Corresponding author]
• Magneto-photoluminescence spectroscopy of ZnMnTe/ZnMgTe spin superlattice
  L.H. Bai; Z.H. Chen; F.Z. Wang; S.H. Huang; H. Xiong; I. Souma; A. Murayama; Y. Oka; S.C. Shen
  Journal of Luminescence, 119-120, 541-545, 2006, [Peer-reviewed]
• Efficient spin injection into self-assembled quantum dots via LO-phonon-assisted resonant electron tunneling
  A. Murayama; T. Asahina; K. Nishibayashi; I. Souma; Y. Oka
  Applied Physics Letters, 88, 023114, 2006, [Peer-reviewed], [Lead author, Corresponding author]
• Coupling of quantum states in a single CdSe/ZnSe quantum dot molecule
  H. Xiong; Z.H. Chen; K. Hyomi; I. Souma; Y.N. Zhang; L.X. Sun; Q.J. Ren; L.H. Bai; S.H. Huang; F.Z. Wang; A. Murayama; Y. Oka; S.C. Shen
  Journal of Luminescence, 119-120, 193, 197, 2006, [Peer-reviewed]
• Transient photoluminescence spectroscopy of spin injection dynamics in double quantum wells of diluted magnetic semiconductors
  K. Kayanuma; K. Seo; K. Nishibayashi; A. Murayama; Y. Oka; I.A. Buyanova; W.M. Chen
  Journal of Luminescence, 119-120, 418, 422, 2006, [Peer-reviewed]
• Nanoscale magnet for semiconductor spintronics
  A. Murayama; M. Sakuma
  Applied Physics Letters, 88, 122504, 2006, [Peer-reviewed], [Corresponding author]
• Dynamical spin separation induced by spin-dependent type-II band alignment in a diluted magnetic double quantum well
  T. Koyama; K. Kayanuma; I. Souma; A. Murayama; Y. Oka
  Applied Physics Letters, 88, 212106, 2006, [Peer-reviewed], [Corresponding author]
• Fabrication and magneto-optical properties of nanostructures of diluted magnetic semiconductors integrated with glass thin films
  A. Murayama; K. Hyomi; M. Sakuma; I. Souma
  Japanese Journal of Applied Physics, 45, 5311, 5316, 2006, [Peer-reviewed], [Lead author, Corresponding author]
• Spin-injection dynamics in a magnetic double quantum well studied by pump-probe absorption spectroscopy
  K. Nishibayashi; I. Souma; A. Murayama; Y. Oka
  Applied Physics Letters, 88, 211108, 2006, [Peer-reviewed], [Corresponding author]
• Spin dynamics in a diluted magnetic semiconductor quantum well studied by pump-probe absorption spectroscopy; Magnetic-field-induced suppression of electron-spin relaxation
  A. Murayama; K. Seo; K. Nishibayashi; I. Souma; Y. Oka
  Applied Physics Letters, 88, 261105, 2006, [Peer-reviewed], [Lead author]
• Density-dependent dynamics of exciton magnetic polarons in ZnMnSe/ZnSSe type II quantum wells
  A.A. Toropov; Ya.V. Terent’ev; S.V. Sorokin; S.V. Ivanov; T. Koyama; K. Nishibayashi; A. Murayama; Y. Oka; J.P. Bergman; I.A. Buyanova; W.M. Chen; B. Monemar
  Physical Review B, 73, 245335, 2006, [Peer-reviewed]
• Magnetic-field-dependent type-II transition induced by resonant electron tunneling from a diluted magnetic semiconductor quantum well into self-assembled quantum dots
  A. Murayama; T. Asahina; K. Nishibayashi; I. Souma; Y. Oka
  Journal of Applied Physics, 100, 084327, 2006, [Peer-reviewed], [Lead author]
• Effect of momentum relaxation on exciton spin dynamics in diluted magnetic semiconductor ZnMnSe/CdSe superlattices
  I.A. Buyanova; G.Yu, Rudko; W.M. Chen; K. Kayanuma; A. Murayama; Y. Oka; A.A. Toropov; S.V. Sorokin; S.V. Ivanov
  Physical Review B, 71, 165203, 2005, [Peer-reviewed]
• Giant Zeeman effects and spin dynamics of excitons in dense self-organized quantum dots of CdSe and Cd1-xMnxSe
  I. Souma; K. Kayanuma; K. Hyomi; K. Nishibayashi; A. Murayama; Y. Oka
  Journal of Superconductivity: incorporating Novel Magnetism, 18, 219, 222, 2005, [Peer-reviewed], [Corresponding author]
• Identification of a dominant mechanism for optical spin injection from a diluted magnetic semiconductor: Spin-conserving energy transfer via localized excitations
  W.M. Chen; I.A. Buyanova; K. Kayanuma; K. Nishibayashi; K. Seo; A. Murayama; Y. Oka; A.A. Toropov; A.V. Lebedev; S.V. Sorokin; S.V. Ivanov
  Physical Review B, 72, 073206, 2005, [Peer-reviewed]
• Efficient spin relaxation in InGaN/GaN and InGaN/GaMnN quantum wells: An obstacle to spin detection
  W.M. Chen; I.A. Buyanova; K. Nishibayashi; K. Kayanuma; K. Seo; A. Murayama; Y. Oka; G. Thaler; R. Frazier; C.R. Abernathy; F.Ren; S.J. Pearton; C.-C. Pan; G.-T. Chen; J.-I. Chyi
  Applied Physics Letters, 87, 192107, 192109, 2005, [Peer-reviewed]
• Giant magneto-optical properties in hybrid nano-structures of diluted magnetic semiconductors with ferromagnetic Co wires
  M. Sakuma; K. Hyomi; I. Souma; A. Murayama; Y. Oka
  Journal of Superconductivity: incorporating Novel Magnetism, 18, 325-, 329, 2005, [Peer-reviewed], [Corresponding author]
• Spin injection processes in ZnSe-based double quantum dots of diluted magnetic semiconductors
  T. Tomita; A. Uetake; T. Asahina; K. Kayanuma; A. Murayama; Y. Oka
  Journal of Superconductivity: incorporating Novel Magnetism, 18, 405, 410, 2005, [Peer-reviewed]
• Pump-probe spectroscopy of exciton spin injection process in diluted magnetic quantum wells
  K. Nishibayashi; K. Seo; K. Kayanuma; T. Tomita; A. Murayama; Y. Oka
  Journal of Superconductivity: incorporating Novel Magnetism, 18, 399, 404, 2005, [Peer-reviewed]
• Transient spectroscopy of optical spin injection in ZnMnSe/ZnCdSe quantum structures
  I.A. Buyanova; W.M. Chen; K. Kayanuma; Z.H. Chen; A. Murayama; Y. Oka; A.A. Toropov; S.V. Sorokin; A.V. Kebedev; S.V. Ivanov
  Journal of Superconductivity: incorporating Novel Magnetism, 18, 371, 373, 2005, [Peer-reviewed]
• Light scattering study on hybrid structures of Zn1-x-yCdxMnySe quantum wells with ferromagnetic Co wires
  M. Sakuma; K. Hyomi; I. Souma; A. Murayama; Y. Oka
  Physica Status Solidi (b), 241, 664, 667, 2004, [Peer-reviewed], [Corresponding author]
• Dynamics in magneto-optical properties of digital magnetic Zn1-xCdxSe quantum wells
  E. Nakayama; K. Kayanuma; T. Tomita; A. Murayama; Z.H. Chen; Y. Oka
  Physica E, 21, 1027, 1031, 2004, [Peer-reviewed], [Corresponding author]
• Interface magnetic properties of MnSe digitally doped in ZnSe-based quantum wells
  A. Murayama; E. Nakayama; T. Tomita; I. Souma; Y. Oka
  Journal of Applied Physics, 95, 7408, 7410, 2004, [Peer-reviewed], [Lead author, Corresponding author]
• Dynamic magnetic properties of epitaxial MnAs thin films studied by spin-wave Brillouin scattering
  A. Murayama; K. Hyomi; M. Sakuma; Y. Oka; J. Okabayashi; M. Mizuguchi; H. Kuramochi; H. Akinaga
  Journal of Applied Physics, 95, 6619, 6621, 2004, [Peer-reviewed], [Lead author, Corresponding author]
• Giant Zeeman effect of excitons in a hybrid nanostructure of diluted magnetic semiconductor quantum well sandwiched in Co wires
  M. Sakuma; K. Hyomi; I. Souma; A. Murayama; Y. Oka
  Applied Physics Letters, 85, 6203, 6205, 2004, [Peer-reviewed], [Corresponding author]
• Efficient spin depolarization in ZnCdSe spin detector: an important factor limiting optical spin injection efficiency in ZnMnSe/ZnCdSe spin light-emitting structures
  W.M. Chen; I.A. Buyanova; K. Kayanuma; Z.H. Chen; A. Murayama; Y. Oka; A.A. Toropov; S.V. Sorokin; S.V. Ivanov; P.S. Kop'e
  Applied Physics Letters, 85, 5260, 5262, 2004, [Peer-reviewed]
• Effects of digital doping of Mn on giant magneto-optical properties of Zn1-xMnxSe quantum wells
  E. Nakayama; T. Uchida; I. Souma; Z.H. Chen; A. Murayama; Y. Oka
  Journal of Superconductivity: incorporating Novel Magnetism, 16, 407, 410, 2003, [Peer-reviewed], [Corresponding author]
• Magnetic-field-induced level crossing and the spin dynamics of excitons in Zn1-xMnxTe/ZnTe quantum wells
  S. Shirotori; K. Kayanuma; T. Tomita; Z.H. Chen; M.C. Debnath; I. Souma; A. Murayama; Y. Oka
  Journal of Superconductivity: incorporating Novel Magnetism, 16, 457, 460, 2003, [Peer-reviewed], [Corresponding author]
• Submicron scale hybrid structures of diluted magnetic semiconductor quantum wells with ferromagnetic Co wires
  M. Sakuma; K. Hyomi; I. Souma; A. Murayama; Y. Oka
  Journal of Applied Physics, 94, 6423, 6429, 2003, [Peer-reviewed], [Corresponding author]
• Spin dynamics of excitons and magnetic ions in Cd1-xMnxTe/Cd1-yMgyTe quantum wells
  Z.H. Chen; H. Sakurai; K .Seo; K. Kayanuma; T. Tomita; A. Murayama; Y. Oka
  Physica B, 340-342, 890, 894, 2003, [Peer-reviewed]
• Spin injection and spin switching of excitons in coupled quantum wells of diluted magnetic semiconductors
  K. Kayanuma; S. Shirotori; Z.H. Chen; T. Tomita; A. Murayama; Y. Oka
  Physica B, 340-342, 882, 885, 2003, [Peer-reviewed]
• Subpicosecond dynamical renormalization of spin-polarized electron-hole plasma in Cd1-xMnxTe
  Z.H. Chen; H. Sakurai; T. Tomita; K. Kayanuma; A. Murayama; Y. Oka
  Physica E, 21, 1022, 1026, 2003, [Peer-reviewed]
• Exciton recombination processes in Cd1-xMnxSe/ZnSe quantum dots under magnetic fields
  K. Shibata; E. Nakayama; I. Souma; A. Murayama; Y. Oka
  Physica Status Solidi (b), 229, 473, 476, 2002, [Peer-reviewed]
• Spin-dependent carrier confinements and radiative recombinations in Zn1-xMnxTe/Zn1-yMgyTe spin superlattices
  M.C. Debnath; Z.H. Chen; I. Souma; K. Sato; A. Murayama; Y. Oka
  Physica Status Solidi (b), 229, 695, 699, 2002, [Peer-reviewed]
• Exciton spin injection in CdTe/Cd1-xMnxTe double quantum wells
  K. Kayanuma; M.C. Debnath; I. Souma; Z.H. Chen; A. Murayama; M. Kobayashi; H. Miyazaki; Y. Oka
  Physica Status Solidi (b), 229, 761, 764, 2002, [Peer-reviewed]
• Surface magnetic anisotropy of Co(0001) and effects of ultrathin Cu-overlayers studied by in-situ spin-wave Brillouin light scattering
  K. Hyomi; A. Murayama; Y. Oka; U. Hiller; C.M. Falco
  Applied Physics Letters, 80, 282, 284, 2002, [Peer-reviewed], [Corresponding author]
• Magneto-optical properties and exciton dynamics in diluted magnetic semiconductor nanostructures
  Y. Oka; K. Kayanuma; S. Shirotori; A. Murayama; I. Souma; Z.H. Chen
  Journal of Luminescence, 100, 175, 190, 2002, [Peer-reviewed]
• Excitonic Properties and Dynamics in Diluted Magnetic Semiconductor Quantum Nanostructures
  Y. Oka; K. Kayanuma; E. Nakayama; S. Shiratori; I. Souma; T. Tomita; Z.H. Chen; A. Murayama
  Nonlinear Optics, 29, 491, 499, 2002, [Peer-reviewed]
• Brillouin study of long-wavelength spin waves in quasimonatomic Co films with uniaxial perpendicular magnetic anisotropy
  A. Murayama; K. Hyomi; J. Eickmann; C.M. Falco
  Physical Review B, 61, 8984, 8992, 2000, [Peer-reviewed], [Lead author, Corresponding author]
• Micro magnetic study of CoPt-SiO2 granular films by the spin-wave Brillouin scattering
  A. Kikitsu; A. Murayama; K. Hyomi; C.M. Falco
  Journal of Applied Physics, 87, 6944, 6946, 2000, [Peer-reviewed]
• Anomalous magneto-optical properties of EuTe induced by magnetic polarons
  Z.H. Chen; W. Heiss; I. Souma; A. Murayama; Y. Oka
  Journal of Superconductivity: incorporating Novel Magnetism, 16, 403, 405, 2000, [Peer-reviewed]
• Magnetic inhomogeneity in ultrathin Co films studied by spin-wave Brillouin scattering
  K. Hyomi; A. Murayama; J. Eickmann; C.M. Falco
  Journal of Magnetism and Magnetic Materials, 198-199, 528, 530, 1999, [Peer-reviewed], [Corresponding author]
• Perpendicular magnetic anisotropy in Au/Co/Au(111) sandwiched films: Interface anisotropy and effect of strain
  K. Hyomi; A. Murayama; J. Eickmann; C.M. Falco
  Journal of Magnetism and Magnetic Materials, 198-199, 378, 380, 1999, [Peer-reviewed], [Corresponding author]
• Low frequency excitation of spin-wave Brillouin scattering in ultra-thin Co/Au(111) films with a perpendicular anisotropy
  A. Murayama; K. Hyomi; J. Eickmann; C.M. Falc
  Journal of Magnetism and Magnetic Materials, 198-199, 372, 374, 1999, [Peer-reviewed], [Lead author, Corresponding author]
• Spin-wave Brillouin scattering in quasimonatomic Co films
  A. Murayama; K. Hyomi; J. Eickmann; C.M. Falco
  Journal of Applied Physics, 85, 5051, 5053, 1999, [Peer-reviewed], [Lead author, Corresponding author]
• Strain dependence of the interface perpendicular magnetic anisotropy in epitaxial Co/Au/Cu(111) films
  A. Murayama; K. Hyomi; J. Eickmann; C.M. Falco
  Physical Review B, 60, 15245, 15250, 1999, [Peer-reviewed], [Lead author, Corresponding author]
• Enhancement of elastic-light-scattering due to the magnetization instability in ultrathin magnetic films
  A. Murayama; K. Hyomi; C.M. Falco
  Physical Review B, 60, 6281, 6284, 1999, [Peer-reviewed], [Lead author, Corresponding author]
• Effect of an ultrathin Au interlayer at a Co/Cu(111) interface on the magnetic properties
  A. Murayama; K. Hyomi; J. Eickmann; C.M. Falco
  Journal of Applied Physics, 83, 613, 615, 1998, [Peer-reviewed], [Lead author, Corresponding author]
• Effect of an Au underlayer on perpendicular magnetic anisotropy in Au/Co/Au(111) sandwich films
  A. Murayama; K. Hyomi; J. Eickmann; C.M. Falco
  IEEE Transactions on Magnetics, 34, 1198, 1200, 1998, [Peer-reviewed], [Lead author, Corresponding author]
• Underlayer-induced perpendicular magnetic anisotropy in ultrathin Co/Au/Cu(111) films: A spin-wave Brillouin scattering study
  A. Murayama; K. Hyomi; J. Eickmann; C.M. Falco
  Physical Review B, 58, 8596, 8604, 1998, [Peer-reviewed], [Lead author, Corresponding author]
• Grain structure and magnetic clustering in SiO2 added CoNiPt granular films
  A. Murayama; K. Hyomi; K. Ohshima; M. Miyamura; M. Maekawa; S. Kondoh
  Journal of Applied Physics, 81, 3925, 3927, 1997, [Peer-reviewed], [Lead author, Corresponding author]
• Spin-wave Brillouin study of ultra-thin Co/Au(111) films with perpendicular magnetic anisotropy
  A. Murayama; K. Hyomi; J. Eickmann; C.M. Falco
  Journal of Applied Physics, 82, 6186, 6192, 1997, [Peer-reviewed], [Lead author, Corresponding author]
• Magnetic interaction and remanence properties in CoNiPt(SiO2) granular films for high-density longitudinal recording
  A. Murayama; K. Ohshima; M. Miyamura; M. Maekawa; S. Kondoh
  Journal of Applied Physics, 79, 7916, 7919, 1996, [Peer-reviewed], [Lead author, Corresponding author]
• Effect of oxide addition on magnetic and structural properties of CoNiPt alloy films
  A. Murayama; S. Kondoh; M. Miyamura
  Journal of Applied Physics, 75, 6147, 6149, 1994, [Peer-reviewed], [Lead author, Corresponding author]
• Magnetic and structural properties of CoNiPt(SiO2) alloy films for high-density longitudinal recording
  A. Murayama; M. Miyamura; S. Kondoh
  Journal of Applied Physics, 76, 5361, 5370, 1994, [Peer-reviewed], [Lead author, Corresponding author]
• Chemical segregation in CoNiPt(SiO2) alloy film
  A. Murayama; M. Miyamura; S. Kondoh
  Applied Physics Letters, 65, 1186, 1188, 1994, [Peer-reviewed], [Lead author, Corresponding author]
• Brillouin spectroscopy of spin waves in sputtered CoPt alloy films and Co/Pt/Co multilayered films
  A. Murayama; M. Miyamura; K. Nishiyama; K. Miyata; Y. Oka
  Journal of Applied Physics, 69, 5661, 5663, 1991, [Peer-reviewed], [Lead author, Corresponding author]
• Interlayer exchange coupling in Co/Cr/Co double-layered recording films studied by spin-wave Brillouin scattering
  A. Murayama; M. Miyamura; K. Miyata; Y. Oka
  IEEE Transactions on Magnetics, 27, 5064, 5066, 1991, [Peer-reviewed], [Lead author, Corresponding author]
• Brillouin study of spin waves in sputtered CoNiPt alloy films
  A. Murayama; M. Miyamura; S. Ishikawa; Y. Oka
  Journal of Applied Physics, 67, 410, 413, 1990, [Peer-reviewed], [Lead author, Corresponding author]
• Characterization of evaporated amorphous WO3 films by Raman and FTIR spectroscopies
  Y. Shigesato; A. Murayama; T. Kamimori; K. Matsuhiro
  Applied Surface Science, 33/34, 804, 811, 1988, [Peer-reviewed]
• Picosecond spectroscopy of Raman scattering and luminescence from rhodamine 6G molecules adsorbed on Ag surfaces
  A. Murayama; Y. Oka; H. Fujisaki
  Surface Science, 158, 222, 228, 1986, [Peer-reviewed]
• Picosecond transient spectroscopy of fluorescence in rhodamine 6G adsorbed electrochemically on Ag surface
  A. Murayama; Y. Oka; H. Fujisaki
  Solid State Communications, 55, 91, 95, 1985, [Peer-reviewed]

• 物性科学 : 理工学基礎
  坂田, 亮; 村山, 明宏
  培風館, Jul. 2022, 9784563067922, xiv, 327p, Japanese
• 量子ドット（エレクトロニクスの最前線）
  村山明宏, 自己組織化量子ドットにおける高効率スピン注入とその制御技術
  株式会社エヌ・ティー・エス, Mar. 2011, [Contributor]
• 機能性ガラス・ナノガラスの最新技術
  村山明宏; 岡泰夫, 磁性半導体ナノガラスの作製
  ㈱エヌ・ティー・エス, Jul. 2006, [Contributor]
• 〔Major achievements〕Optical properties of condensed matter and applications
  A. Murayama; Y. Oka, Optical Properties and Spin Dynamics of Diluted Magnetic Semiconductor Nanostructures
  John Wiley, 2006, 0470021926, xiv, 434 p., English, [Contributor]

• Light-Absorbing Layer Thickness Dependence of Polarization-Sensitive Photodiodes Based on Dilute Nitride GaNAs
  D. Mineyama; I. Tanaka; K. Nakama; H. Hashimoto; K. Minehisa; J. Takayama; F. Ishikawa; A. Murayama; S. Hiura
  2025 International Conference on Solid State Devices and Materials (SSDM2025), Sep. 2025, English, Poster presentation
• Effect of Stacking Number of InGaAs Quantum Dot Active Layers on Circularly Polarized Electroluminescence Properties of Spin-Polarized Light-Emitting Diodes
  I. Tanaka; D. Mineyama; A. Morita; H. Kise; J. Takayama; A. Murayama; S. Hiura
  2025 International Conference on Solid State Devices and Materials (SSDM2025), Sep. 2025, English, Poster presentation
• Bias voltage dependence of the performance of polarization-sensitive photodiode using dilute nitride GaNAs
  D. Mineyama; K. Nakama; H. Hashimoto; K. Minehisa; J. Takayama; A. Subagyo; K. Sueoka; F. Ishikawa; A. Murayama; S. Hiura
  The 10th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2025), Jun. 2025, English, Poster presentation
• Electroluminescence properties of InGaAs quantum dot light-emitting diodes with different stacking number of quantum dot layers
  I. Tanaka; D. Mineyama; K. Etou; A. Morita; H. Kise; J. Takayama; A. Murayama; S. Hiura
  The 10th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2025), Jun. 2025, English, Poster presentation
• Effect of excitation spin density on oscillation characteristics of luminescence circular polarization from InGaAs quantum dots tunnel-coupled with a GaNAs quantum well with magnetic field
  S. Sakano; S. Nomura; J. Takayama; A. Murayama; S. Hiura
  The 10th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2025), Jun. 2025, English, Poster presentation
• Electron spin dynamics of dilute nitride GaNAs-InGaAs quantum dot tunnelcoupled nanostructure sandwiched between AlGaAs barriers
  S. Nomura; H. Kise; J. Takayama; A. Murayama; S. Hiura
  The 10th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2025), Jun. 2025, English, Poster presentation
• Temperature dependence of circularly polarized photoluminescence in dilute nitride InGaAsN quantum dots grown at low temperature
  A. Morita; J. Takayama; A. Murayama; S. Hiura
  37th International Microprocesses and Nanotechnology Conference (MNC 2024), Nov. 2024, English, Oral presentation
• Circularly polarized electroluminescence properties of quantum dot spin-polarized lightemitting diode using GaOx tunneling barrier
  S. Sim; K. Etou; J. Takayama; A. Subagyo; K. Sueoka; A. Murayama; S. Hiura
  37th International Microprocesses and Nanotechnology Conference (MNC 2024), Nov. 2024, English, Poster presentation
• 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, English, Poster presentation
• Electron spin transport properties of GaAs/AlGaAs superlattice barrier under an application of electric field
  K. Etou; J. Takayama; A. Subagyo; K. Sueoka; A. Murayama; S. Hiura
  37th International Microprocesses and Nanotechnology Conference (MNC 2024), Nov. 2024, English, Poster presentation
• Room Temperature Electric Field Control of Electron Spin Polarization in InAs Quantum Dots Tunnel-Coupled with an InGaAs Quantum Well
  H. Kise; S. Hiura; J. Takayama; K. Sueoka; A. Murayama
  23rd International Conference on Molecular-Beam Epitaxy (ICMBE2024), Sep. 2024, English, Poster presentation
• Spin-Polarized Light Emission Properties of InGaAs Quantum Dots Sandwiched between Dilute Nitride GaNAs via GaAs Tunnel Barrier
  S. Nomura; S. Hiura; J. Takayama; A. Murayama
  23rd International Conference on Molecular-Beam Epitaxy (ICMBE2024), Sep. 2024, English, Poster presentation
• Room Temperature Polarization-Dependent Photocurrent Characteristics of Near-Infrared Photodiode Based on Dilute Nitride GaNAs
  D. Mineyama; S. Hiura; K. Nakama; H. Hashimoto; K. Minehisa; J. Takayama; A. Subagyo; K. Sueoka; F. Ishikawa; A. Murayama
  2024 International Conference on Solid State Devices and Materials (SSDM2024), Sep. 2024, English, Poster presentation
• Wafer Scale GaAs/AlGaAs Core-Shell Nanowires on 2-inch Si Substrate Showing Efficient Light Emission/Absorption with High Thermal Stability
  K. Minehisa; H. Hashimoto; K. Nakama; H. Kise; S. Sato; J. Takayama; S. Hiura; A. Murayama; F. Ishikawa
  38th North American Conference on Molecular Beam Epitaxy (NAMBE2024), Jul. 2024, English, Poster presentation
• Effective suppression of spin relaxation at room temperature in dilute nitride InGaAsN quantum dots
  A. Morita; S. Hiura; J. Takayama; A. Murayama
  Compound Semiconductor Week 2024 (CSW2024), Jun. 2024, English, Oral presentation
• Temperature dependence of photoluminescence properties of dilute nitride InGaAsN quantum dots
  A. Morita; S. Hiura; J. Takayama; A. Murayama
  36th International Microprocesses and Nanotechnology Conference (MNC 2023), 17 Nov. 2023, English, Poster presentation
• Room-temperature electron spin transport to InAs quantum dots using a dilute nitride GaNAs/GaAs superlattice barrier
  M. Hosoe; S. Sato; S. Hiura; J. Takayama; A. Murayama
  36th International Microprocesses and Nanotechnology Conference (MNC 2023), 17 Nov. 2023, English, Poster presentation
• Circularly polarized light detection characteristics of spin photodiode based on a dilute nitride GaNAs spin filter
  T. Hioki; K. Etou; S. Hiura; J.Takayama; A. Subagyo; K. Sueoka; A. Murayama
  36th International Microprocesses and Nanotechnology Conference (MNC 2023), 17 Nov. 2023, English, Poster presentation
• Room temperature operation of spin-functional optical devices based on 0D-2D hybrid semiconductor nanostructures
  A. Murayama; S. Hiura
  36th International Microprocesses and Nanotechnology Conference (MNC 2023), 16 Nov. 2023, English, Invited oral presentation
  [Invited]
• Electric-field effects on optical spin polarization in III-V semiconductor quantum-dot-superlattice hybrid nanostructure
  H. Kise; S. Park; S. Hiura; J. Takayama; K. Sueoka; A. Murayama
  The 9th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2023), 06 Jun. 2023, English, Oral presentation
• Bias voltage and temperature dependence of electron-spin polarization in InAs quantum dots tunnel-coupled with a GaNAs quantum well
  S. Park; H. Kise; S. Hiura; J. Takayama; K. Sueoka; A. Murayama
  2022 International Conference on Solid State Devices and Materials (SSDM2022), 29 Sep. 2022, English, Oral presentation
• Room-temperature operation characteristics of a spin-polarized light-emitting diode using InAs quantum dots tunnel-coupled with GaNAs
  K. Etou; S. Hiura; J. Takayama; A. Subagyo; K. Sueoka; A. Murayama
  2022 International Conference on Solid State Devices and Materials (SSDM2022), 28 Sep. 2022, English, Oral presentation
• Structural and optical properties of InAs quantum dots capped with GaAs grown at different rates
  S. Izumi; S. Hiura; J. Takayama; A. Murayama
  The 22nd International Vacuum Congress (IVC-22), 13 Sep. 2022, English, Poster presentation
• Thickness effects of dilute GaAs nitride quantum wells on optical spin properties of tunnel-coupled InAs quantum dots
  S. Sato; M. Hosoe; S. Hiura; J. Takayama; A. Murayama
  The 22nd International Vacuum Congress (IVC-22), 13 Sep. 2022, English, Oral presentation
• Temperature effects on performances of a spin-polarized light emitting diode using p-doped InGaAs quantum dots
  K. Etou; S. Hiura; J. Takayama; S. Park; A. Subagyo; K. Sueoka; A. Murayama
  2021 International Conference on Solid State Devices and Materials (SSDM2021), 2021, English, Oral presentation
• Optical spin properties of InAs quantum dots tunnel-coupled with dilute nitride GaNAs
  S. Sato; Y. Nakamura; S. Park; S. Hiura; J. Takayama; A. Murayama
  2021 International Conference on Solid State Devices and Materials (SSDM2021), 2021, English, Oral presentation
• Electric-field control of electron-spin polarization degree at room temperature in opto-spintronic device using InGaAs quantum dots
  S. Park; S. Hiura; H. Chen; J. Takayama; K. Sueoka; A. Murayama
  2021 International Conference on Solid State Devices and Materials (SSDM2021), 2021, English, Oral presentation
• Fabrication of p-doped quantum dot spin-polarized light-emitting diodes
  K. Etou; S. Hiura; J. Takayama; A. Murayama
  2020 International Conference on Solid State Devices and Materials (SSDM2020), 30 Sep. 2020, English, Oral presentation
  27 Sep. 2020 - 30 Sep. 2020, 29996440;29996438
• Highly efficient electron-photon spin conversion using InGaAs quantum dots with p-doped capping barrier
  S. Sato; S. Hiura; J. Takayama; A. Murayama
  2020 International Conference on Solid State Devices and Materials (SSDM2020), 29 Sep. 2020, English, Oral presentation
  27 Sep. 2020 - 30 Sep. 2020, 29996440;29996438
• Electron-spin dynamics in tunnel-coupled structures of InGaAs well and dot with different p-doping concentrations applied with electric field
  S. Park; H. Chen; S. Hiura; J. Takayama; A. Murayama
  2020 International Conference on Solid State Devices and Materials (SSDM2020), 29 Sep. 2020, English, Oral presentation
  27 Sep. 2020 - 30 Sep. 2020, 29996438;29996440
• Spin relaxation property after spin transfer from a semiconductor superlattice barrier to quantum dots
  S. Hatakeyama; S. Hiura; J. Takayama; A. Murayama
  2020 International Conference on Solid State Devices and Materials (SSDM2020), 29 Sep. 2020, English, Oral presentation
  27 Sep. 2002 - 30 Sep. 2020, 29996440;29996438
• Quantum spin transport to self-assembled InGaAs quantum dots through AlGaAs/GaAs superlattice
  S. Hiura; J. Takayama; T. Kiba; A. Murayama
  Materials Research Meeting (MRM2019), 11 Dec. 2019, English, Poster presentation
• Size-modulation-induced spin amplification in quantum nanocolumns
  S. Hiura; S. Saito; J. Takayama; T. Kiba; A. Murayama
  7th International Workshop on Epitaxial Growth and Fundamental Properties of Semiconductor Nanostructures (SemiconNano2019), 25 Sep. 2019, English, Oral presentation
• Temperature dependence of modal gain at excited states in high-density InGaAs quantum dots by variable stripe length method
  A. Ohtake; S. Hiura; J. Takayama; A. Murayama
  7th International Workshop on Epitaxial Growth and Fundamental Properties of Semiconductor Nanostructures (SemiconNano2019), 25 Sep. 2019, English, Poster presentation
• Temperature-persistent spin relaxation in InGaAs/GaAs dots-in-well structure
  M. Takishita; S. Hiura; J. Takayama; A. Murayama
  7th International Workshop on Epitaxial Growth and Fundamental Properties of Semiconductor Nanostructures (SemiconNano2019), 25 Sep. 2019, English, Poster presentation
• Electric-field-effect optical spin-injection device using p-doped InGaAs quantum dots
  S. Park; H. Chen; S. Hiura; J. Takayama; A. Murayama
  7th International Workshop on Epitaxial Growth and Fundamental Properties of Semiconductor Nanostructures (SemiconNano2019), 25 Sep. 2019, English, Poster presentation
• Temperature-dependent spin dynamics in InGaAs quantum dots embedded with GaAs capping layer grown at low temperature
  Y. Nakamura; S. Hiura; S. Sato; J. Takayama; A. Murayama
  7th International Workshop on Epitaxial Growth and Fundamental Properties of Semiconductor Nanostructures (SemiconNano2019), 25 Sep. 2019, English, Poster presentation
• P-doping effects on temperature-dependent spin dynamics in InGaAs quantum dots
  S. Sato; S. Hiura; J. Takayama; A. Murayama
  7th International Workshop on Epitaxial Growth and Fundamental Properties of Semiconductor Nanostructures (SemiconNano2019), 25 Sep. 2019, English, Poster presentation
• Lateral electronic coupling among self-assembled semiconductor quantum dots promoted by adjoining tunnel-coupled quantum-well potentials
  J. Takayama; S. Hiura; K. Takeishi; T. Kiba; A. Murayama
  Compound Semiconductor Week 2019 (CSW2019), 21 May 2019, English, Oral presentation
• Effects of growth temperature of a capping layer on excited spin properties of In0.5Ga0.5As quantum dots
  Y. Nakamura; S. Hiura; S. Sato; J. Takayama; A. Murayama
  Compound Semiconductor Week 2019 (CSW2019), 21 May 2019, English, Poster presentation
• Effects of p-doping on excited spin states and the dynamics in InGaAs quantum dots
  S. Sato; M. Murakami; Y. Nakamura; S. Hiura; J. Takayama; A. Murayama
  Compound Semiconductor Week 2019 (CSW2019), 20 May 2019, English, Poster presentation
• Electric-field control of optical-spin injection from an InGaAs quantum well to p-doped quantum dots
  S. Park; H. Chen; J. Takayama; S. Hiura; A. Murayama
  Compound Semiconductor Week 2019 (CSW2019), 20 May 2019, English, Poster presentation
• Spin-conserved electron transport to InGaAs quantum dots through GaAs/AlGaAs superlattice
  S. Hiura; J. Takayama; T. Kiba; A. Murayama
  Compound Semiconductor Week 2019 (CSW2019), 20 May 2019, English, Oral presentation
• Temperature Dependence of Interdot Spin Dynamics in Laterally Coupled InGaAs Quantum Dots
  S. Sato; S. Hiura; J. Takayama; A. Murayama
  31st International Microprocesses and Nanotechnology Conference (MNC 2018), 16 Nov. 2018, English, Poster presentation
• Electric-Field Optical Device Controlling Electron-Spin Polarity of InGaAs Quantum Dots
  H. Chen; J. Takayama; S. Hiura; K. Sueoka; A. Murayama
  31st International Microprocesses and Nanotechnology Conference (MNC 2018), 16 Nov. 2018, English, Poster presentation
• Temperature-Persistent High Spin Polarization and Its Dynamics in InGaAs Quantum Dots Embedded in a GaAs Quantum Well
  M. Takishita; S. Hiura; J. Takayama; A. Murayama
  31st International Microprocesses and Nanotechnology Conference (MNC 2018), 15 Nov. 2018, English, Poster presentation
• Modal Gain at Excited States in High-Density InGaAs Quantum Dots Investigated by Variable Stripe Length Method
  A. Ohtake; S. Hiura; A. Washida; J. Takayama; A. Murayama
  31st International Microprocesses and Nanotechnology Conference (MNC 2018), 15 Nov. 2018, English, Poster presentation
• Optical Study on Thermal Activation Processes of Carrier Dynamics in In0.3Ga0.7N Nanodisks
  Y. Chen; T. Kiba; J. Takayama; A.Higo; T. Tanikawa; S. Samukawa; A. Murayama
  31st International Microprocesses and Nanotechnology Conference (MNC 2018), 15 Nov. 2018, English, Poster presentation
• Excited Spin Engineering of In0.5Ga0.5As Quantum Dots by an Adjacent Two-Dimensional In0.1Ga0.9As Quantum Well Potential
  S. Hiura; K. Takeishi; J. Takayama; T. Kiba; A. Murayama
  31st International Microprocesses and Nanotechnology Conference (MNC 2018), 14 Nov. 2018, English, Oral presentation
• Effects of electrical field on circularly polarized photoluminescence in InGaAs-based coupled nanostructures of quantum dots and a well
  H. Chen; J. Takayama; S. Hiura; A. Subagyo; K. Sueoka; A. Murayama
  The 12th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials (EXCON2018), 12 Jul. 2018, English, Poster presentation
• High-temperature carrier dynamics responsible for a non-radiative process in InGaN nanodisks fabricated by top-down nanotechnology
  Y. Chen; T. Kiba; J. Takayama; A. Higo; T. Tanikawa; S. Samukawa; A. Murayama
  The 12th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials (EXCON2018), 12 Jul. 2018, English, Poster presentation
• Temperature-dependent spin dynamics in InGaAs/GaAs dots-in-well structure
  M. Takishita; K. Takeishi; S. Hiura; J. Takayama; A. Washida; A. Ohtake; S. Saito; A. Murayama
  The 12th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials (EXCON2018), 12 Jul. 2018, English, Poster presentation
• Influence of vertical interdot coupling on energy-dependent modal gain of InGaAs quantum dots
  A. Ohtake; A. Washida; S. Hiura; J. Takayama; M. Takishita; S. Saito; A. Murayama
  The 12th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials (EXCON2018), 10 Jul. 2018, English, Poster presentation
• Persistent high spin polarization induced by interdot spin transfer among coupled excited states of InGaAs quantum dots
  S. Hiura; K. Takeishi; A. Washida; J. Takayama; A. Ohtake; M. Takishita; S. Saito; A. Murayama
  The 12th International Conference on Excitonic and Photonic Processes in Condensed Matter and Nano Materials (EXCON2018), 10 Jul. 2018, English, Oral presentation
• 〔Major achievements〕Spin transfer dynamics in III-V compound semiconductor quantum dots integrated with layered quantum structures
  Akihiro Murayama
  The 30th International Microprocesses and Nanotechnology Conference (MNC2017), 08 Nov. 2017, English, Invited oral presentation
  [Invited]
• Emission Enhancement and its dynamics of Alq3 with Surface Plasmon Resonance of Ag Nanoparticles
  K. Masui; T. Kiba; A. Sato; K. Yanome; M. Kawamura; Y. Abe; K. H. Kim; H. D. Kim; J. Takayama; A. Murayama
  International Thin Films Conference, 17 Oct. 2017, English, Poster presentation
• Time-resolved Photoluminescence Study of Alq3 Thin Film with Plasmonic Ag Nanotriangle Array Fabricated by Nanosphere Lithography
  K. Yanome; T. Kiba; K. Masui; M. Kawamura; Y. Abe; K. H. Kim; M. Takase; J. Takayama; A. Murayama
  International Thin Films Conference, 17 Oct. 2017, English, Poster presentation
• Optically coupled excitons in a single coupled-quantum-dot structure via dipole-dipole interaction
  H. D. Kim; A. Murayama; K. Kyhm; R. A. Taylor; J. S. Kim
  20th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON20), 18 Jun. 2017, English, Poster presentation
• Fabrication of GaAs quantum nanodisk by bio-template, neutral beam etching, and asymmetric AlGaAs barrier regrowth and its optical response
  A. Higo; Y. Chen; T. Kiba; C. Thomas; J. Takayama; A. Imoto; S. Miyazaki; T. Kamikawa; M. Tanaka; I. Yamashita; Y. Wang; H. Sodabanlu; M. Sugiyama; Y. Nakano; A. Murayama; S. Samukawa
  SPIE Photonics WEST 2017, 17 Feb. 2017, English, Oral presentation
• 〔Major achievements〕Spin-Functional Photoelectric Conversion Utilizing III-V Compound Semiconductor Quantum Dots
  Akihiro Murayama
  6th Annual World Congress of Nano Science & Technology (Nano-S&T 2016), 27 Oct. 2016, English, Invited oral presentation
  [Invited]
• Pump-probe study of temperature-dependent spin relaxation in GaAs quantum disks fabricated by fully top-down lithography using Bio-templates
  T. Kiba; T. Tanaka; A. Higo; C. Thomas; Y. Tamura; S. Samukawa; A. Murayama
  16th IEEE International Conference on Nanotechnology, 23 Aug. 2016, English, Poster presentation
• Electric-field control of spin states in InGaAs-based coupled nanostructures of quantum dots and well
  Y. Akei; J. Takayama; K. Takeishi; K. Itabashi; M. Urabe; A. Murayama
  16th IEEE International Conference on Nanotechnology, 23 Aug. 2016, English, Poster presentation
• Ultrahigh-density self-assembled quantum dots of InGaAs and suppression of optical state-filling effect
  M. Urabe; K. Takeishi; J. Takayama; K. Itabashi; S.L. Chen; A. Murayama
  16th IEEE International Conference on Nanotechnology, 23 Aug. 2016, English, Poster presentation
• Transient photoluminescence in InGaN nano-disks fabricated by nano-scale neutral-beam etching utilizing bio-nano templates
  Y. Chen; S.L. Chen; T. Kiba; C.Y. Lee; C. Thomas; Y.C. Lai; A. Higo; S. Samukawa; A. Murayama
  16th IEEE International Conference on Nanotechnology, 23 Aug. 2016, English, Poster presentation
• Growth optimization of spin-transport barriers used for spin-polarized light-emitting diodes based on InGaAs quantum dots
  K. Itabashi; K. Takeishi; M. Urabe; J. Takayama; S.L. Chen; A. Murayama
  16th IEEE International Conference on Nanotechnology, 23 Aug. 2016, English, Poster presentation
• Transient photoluminescence study on spin dynamics in InGaAs-based coupled nanostructures of quantum dots with quantum wells
  K. Takeishi; S.L. Chen; J. Takayama; K. Itabashi; M. Urabe; A. Murayama
  16th IEEE International Conference on Nanotechnology, 23 Aug. 2016, English, Poster presentation
• InGaN Quantum Nanodisks fabrication by Bio-Template and Neutral Beam etching
  Y.C. Lai; A. Higo; C. Thomas; C.Y. Lee; T. Tanikawa; K. Shojiki; S. Kuboya; R. Katayama; T. Kiba; I. Yamashita; A. Murayama; P. Yu; Seiji Samukawa
  American Vacuum Society – AVS 62nd International Symposium and Exhibition, 23 Oct. 2015, English, Poster presentation
• Room temperature operation of GaAs/AlGaAs quantum nanodisks light emitting diodes fabricated by fusion of bio-template and neutral beam etching
  Y.C. Lai; A. Higo; C. Thomas; T. Kiba; J. Takayama; M. Sugiyama; Y. Nakano; P. Yu; A. Murayama; S. Samukawa
  47th International Conference on Solid State Devices and Materials, 29 Sep. 2015, English, Poster presentation
• Phonon-assisted efficient spin injection in InGaAs quantum well-quantum dot tunnel-coupled structures
  S.L. Chen; T. Kiba; J. Takayama; A. Murayama
  47th International Conference on Solid State Devices and Materials, 29 Sep. 2015, English, Oral presentation
• Effect of remote doping on photoluminescence and carrier spin dynamics in InGaAs quantum dots
  D. Yamazaki; S.L. Chen; J. Takayama; A. Murayama
  47th International Conference on Solid State Devices and Materials, 29 Sep. 2015, English, Poster presentation
• High-density self-assembled quantum dots of InGaAs for ultrafast and efficient spin injection
  J. Takayama; T. Kiba; T. Yamamura; D. Yamazaki; S.L. Chen; A. Murayama
  47th International Conference on Solid State Devices and Materials, 29 Sep. 2015, English, Oral presentation
• Temperature dependences of spin-injection dynamics and spin-polarized electroluminescence in InGaAs quantum dots
  Y. Nomura; Y. Akei; J. Takayama; T. Kiba; A. Subagyo; T. Yamamura; D. Yamazaki; K. Sueoka; A. Murayama
  47th International Conference on Solid State Devices and Materials, 29 Sep. 2015, English, Poster presentation
• Fabrication of InGaN/GaN nanodisk structure by using bio-template and neutral beam etching process
  Y.C. Lai; A. Higo; C.Y. Lee; C. Thomas; T. Tanikawa; K. Shojiki; S. Kuboya; R. Katayama; T. Kiba; P. Yu; I. Yamashita; A. Murayama; S. Samukawa
  15th International IEEE Conference on Nanotechnology, 30 Jul. 2015, English, Oral presentation
• Optical study of temperature-dependent spin injection and relaxation dynamics in InGaAs quantum well-quantum dot tunnel-coupled structure
  S.L. Chen; T. Kiba; X.J. Yang; J. Takayama; A. Murayama
  17th International Conference on Modulated Semiconductor Structures, 30 Jul. 2015, English, Poster presentation
• Top-down InGaAs/GaAs nanopillars fabrication using a bio-nano process and a neutral beam etching process
  C. Thomas; K. Yoshikawa; C.Y. Lee; Y. Tamura; A. Higo; T. Kiba; A. Murayama; I. Yamashita; S. Samukawa
  American Vacuum Society – AVS 61st. International Symposium and Exhibition, 13 Nov. 2014, English, Poster presentation
• 〔Major achievements〕Crystal growth of III-V compound semiconductor nanostructures and transient spin-related optical phenomena
  Akihiro Murayama
  Collaborative Conference on Crystal Growth (3CG2014), 04 Nov. 2014, English, Invited oral presentation
  [Invited]
• Suppression of exciton-spin relaxation induced by artificial lateral quantum confinement in GaAs
  T. Kiba; T. Tanaka; Y. Tamura; C. Thomas; T. Kaizu; Y. Okada; S. Samukawa; A. Murayama
  18th International Conference on Molecular Beam Epitaxy, 12 Sep. 2014, English, Oral presentation
• Optimization of growth conditions of self-assembled InGaAs quantum dots suitable for spin injection
  J. Takayama; T. Yamamura; X. Yang; T. Kiba; A. Subagyo; K. Sueoka; A. Murayama
  18th International Conference on Molecular Beam Epitaxy, 11 Sep. 2014, English, Poster presentation
• Effects of spin density on the spin-tunneling dynamics from a quantum well into self-assembled quantum dots of InGaAs
  T. Yamamura; T. Kiba; X. Yang; J. Takayama; A. Subagyo; K. Sueoka; A. Murayama
  18th International Conference on Molecular Beam Epitaxy, 11 Sep. 2014, English, Poster presentation
• Electrical spin injection from Fe electrodes into InGaAs-based quantum structures
  Y. Nomura; J. Takayama; T. Kiba; Y. Sasaki; T. Yamamura; X. Yang; A. Subagyo; K. Sueoka; A. Murayama
  18th International Conference on Molecular Beam Epitaxy, 11 Sep. 2014, English, Poster presentation
• Quantum GaAs nanodisk light emitting diode fabricated by ultimate top-down neutral beam etching
  Y. Tamura; C. Thomas; T. Kiba; Y. Wang; H. Sodabanlu; J. Takayama; M. Sugiyama; Y. Nakano; I. Yamashita; A. Murayama; S. Samukawa
  24th International Semiconductor Laser Conference, 09 Sep. 2014, English, Poster presentation
• Electron g-factor and spin-relaxation in GaAs quantum disks fabricated by fully top-down lithography
  T. Tanaka; T. Kiba; Y. Tamura; A. Higo; S. Samukawa; A. Murayama
  18th International Conference on Molecular Beam Epitaxy, 08 Sep. 2014, English, Poster presentation
• Narrow line-width photoluminescence spectrum of GaAs nanodisks fabricated using bio-template ultimate top-down processes
  Y. Tamura; A. Higo; T. Kiba; C. Thomas; Y. Wang; H. Sodabanlu; I. Yamashita; M. Sugiyama; Y. Nakano; A. Murayama; S. Samukawa
  14th IEEE International Conference on Nanotechnology, 19 Aug. 2014, English, Poster presentation
• Fabrication of InGaAs quantum nanodisk array by using bio-template and top-down etching processes
  K. Yoshikawa; A. Higo; C.Y. Lee; Y. Tamura; C. Thomas; T. Kiba; S. Ishii; H. Sodabanlu; Y. Wang; M. Sugiyama; Y. Nakano; I. Yamashita; A. Murayama; S. Samukawa
  14th IEEE International Conference on Nanotechnology, 19 Aug. 2014, English, Poster presentation
• Fabrication of InGaAs quantum nanodisk by using Bio-template and neutral beam etching processes
  K. Yoshikawa; A. Higo; C.Y. Lee; Y. Tamura; C. Thomas; T. Kiba; S. Ishii; H. Sodabanlu; Y. Wang; M. Sugiyama; Y. Nakano; I. Yamashita; A. Murayama; S. Samukawa
  6th IEEE International Nanoelectronics Conference, 30 Jul. 2014, English, Poster presentation
• Optical characteristics of GaAs quantum nanodisks by the combination of bio-template ultimate top-down process
  A. Higo; T. Kiba; Y. Tamura; S. Ishii; C. Thomas; T. Ozaki; A. Murayama; S. Samukawa
  6th IEEE International Nanoelectronics Conference, 30 Jul. 2014, English, Oral presentation
• GaAs/AlGaAs quantum nanodisks by using neutral beam etching and their optical response
  Y. Tamura; A. Higo; T. Kiba; C. Thomas; T. Okada; W. Yunpeng; H. Sodabanlu; M. Sugiyama; Y. Nakano; A. Murayama; S. Samukawa
  6th IEEE International Nanoelectronics Conference, 30 Jul. 2014, English, Poster presentation
• New origins of lasing in ZnO; temperature dependence of modal gain contour map
  C. Cho; A. Murayama; K. Kyhm
  6th IEEE International Nanoelectronics Conference, 30 Jul. 2014, English, Oral presentation
• Quantum energy levels simulation for InGaAs/GaAs quantum nanodisks fabricated by ultimate top-down process
  S. Ishii; A. Higo; K. Yoshikawa; Y. Tamura; T. Kiba; A. Murayama; Y. Li; S. Samukawa
  6th IEEE International Nanoelectronics Conference, 29 Jul. 2014, English, Poster presentation
• Electrical spin injection in light-emitting diodes with InGaAs-based quantum structures
  Y. Nomura; T. Kiba; J. Takayama; Y. Sasaki; T. Yamamura; A. Subagyo; K. Sueoka; A. Murayama
  6th IEEE International Nanoelectronics Conference, 29 Jul. 2014, English, Poster presentation
• Effects of electric field on carrier and spin dynamics in InGaAs-based coupled quantum structures
  J. Takayama; T. Kiba; T. Yamamura; Y. Nomura; A. Subagyo; K. Sueoka; A. Murayama
  6th IEEE International Nanoelectronics Conference, 29 Jul. 2014, English, Poster presentation
• Ultrafast spin tunneling from a 2-dimesional electron system into self-assembled quantum dots of InGaAs
  T. Yamamura; T. Kiba; X.J. Yang; J. Takayama; A. Subagyo; K. Sueoka; A. Murayama
  6th IEEE International Nanoelectronics Conference, 29 Jul. 2014, English, Poster presentation
• Longitudinal and transvers electron-spin relaxation times in GaAs nanodisks fabricated by bio-nano templates and damage-free neutral-beam etching
  T. Tanaka; T. Kiba; Y. Tamura; C. Thomas; A. Higo; S. Samukawa; A. Murayama
  6th IEEE International Nanoelectronics Conference, 29 Jul. 2014, English, Poster presentation
• Ultrafast carrier capture in high optical quality GaAs nanodisks fabricated by bio-nano templates and damage-free neutral-beam etching
  T. Kiba; A. Higo; Y. Tamura; C. Thomas; S. Samukawa; A. Murayama
  6th IEEE International Nanoelectronics Conference, 29 Jul. 2014, English, Poster presentation
• 〔Major achievements〕Dynamics of photo-excited carriers and spin-related phenomena in III-V semiconductor nanostructures
  Akihiro Murayama
  IEEE 6th International Nanoelectronics Conference, 29 Jul. 2014, English, Invited oral presentation
  [Invited]
• GaAs/AlGaAs stacked layers etched by neutral beam for the fabrication of quantum dot structures
  Y. Tamura; C. Thomas; A. Higo; T. Kiba; A. Murayama; S. Samukawa
  3rd International Symposium on Next-Generation Electronics, 10 May 2014, English, Oral presentation
• Full 3D quantum energy level simulation for GaAs/AlGaAs quantum nanodisks fabricated by ultimate top-down pocess
  S. Ishii; A. Higo; Y. Tamura; T. Kiba; A. Murayama; Y. Li; S. Samukawa
  3rd International Symposium on Next-Generation Electronics, 10 May 2014, English, Oral presentation
• Optically probed electron-spin relaxation in GaAs nanostructures
  T. Tanaka; T. Kiba; A. Murayama
  Seoul National University and Hokkaido University 2013 International Workshop on New Frontiers in Convergence Science and Technology, 13 Dec. 2013, English, Poster presentation
• Dynamics pf photo-excited carriers in III-V semiconductor nanostructures
  Akihiro Murayama
  Seoul National University and Hokkaido University 2013 International Workshop on New Frontiers in Convergence Science and Technology, 13 Dec. 2013, English, Oral presentation
• The fabrication of GaAs quantum nanodisks combination of bio-template, neutral beam etching and MOVPE regrowth
  A. Higo; Y.e Tamura; T. Kiba; C. Thomas; W. Yunpeng; M. Sugiyama; Y. Nakano; A. Murayama; S. Samukawa
  IEEE Nanotechnology Materials and Device Conference, 07 Oct. 2013, English, Oral presentation
• 〔Major achievements〕Dynamics of photo-excited carriers and the spin states in III-V semiconductor nanostructures; application to quantum-dot lasing
  Akihiro Murayama
  3rd Annual World Congress of Nano Science and Technology, 28 Sep. 2013, English, Invited oral presentation
  [Invited]
• High density and high aspect ratio GaAs/AlGaAs nanopillar array fabricated by fusion of bio-template and neutral beam etching
  Y. Tamura; A. Higo; T. Kiba; W. Yunpeng; C. Thomas; T. Okada; W. Hu; A. Murayama; M. Sugiyama; Y. Nakano; S. Samukawa
  2013 Internatinal Conference on Solid State Devices and Materials, 25 Sep. 2013, English, Poster presentation
• Electron-spin dynamics in GaAs quantum wells coupled with II-VI diluted magnetic semiconductors
  Akihiro Murayama
  NSF Workshop on US-Japan Frontiers in Novel Photonic-Magnetic Devices, 21 Sep. 2013, English, Oral presentation
• Dynamics of exciton-spin relaxation in GaAs nanodisks fabricated by fully-top-down and damage-free lithography
  T. Kiba; K. Suzaki; Y. Tamura; M. Igarashi; C. Thomas; W. Hu; T. Kaizu; Y. Okada; S. Samukawa; A. Murayama
  18th International Conference on Dynamical Processes in Excited States of Solids, 09 Aug. 2013, English, Oral presentation
• Photoluminescence of high-density and sub-20-nm GaAs nanodisks fabricated with a neutral Beam etching process and MOVPE regrowth for high performance QDs devices
  Y. Tamura; A. Higo; T. Kiba; W. Yunpeng; M. Igarashi; C. Thomas; W. Hu; M.E. Fauzi; A. Murayama; M. Sugiyama; Y. Nakano; S. Samukawa
  13th IEEE International Conference on Nanotechnology, 08 Aug. 2013, English, Poster presentation
• Dynamics of optical spin injection in InGaAs self-assembled quantum dots with various growth conditions
  T. Yamamura; X.J. Yang; T. Kiba; Y. Kuno; J. Takayama; A. Subagyo; K. Sueoka; A. Murayama
  18th International Conference on Dynamical Processes in Excited States of Solids, 06 Aug. 2013, English, Poster presentation
• Transient Kerr effects in GaAs quantum disks fabricated by neutral-beam etching using bio-nano templates
  T. Tanaka; T. Sasaki; T. Kiba; K. Kyhm; Y. Tamura; A. Higo; S. Samukawa; A. Murayama
  18th International Conference on Dynamical Processes in Excited States of Solids, 06 Aug. 2013, English, Poster presentation
• Observation of optical gain in GaAs quantum disks fabricated by neutral-beam etching using bio-nano templates
  K. Suzaki; T. Kiba; K. Kyhm; Y. Tamura; A. Higo; S. Samukawa; A. Murayama
  18th International Conference on Dynamical Processes in Excited States of Solids, 06 Aug. 2013, English, Poster presentation
• Electroluminescence from excited states in InGaAs self-assembled quantum dots
  Y. Sasaki; X.j. Yang; J. Takayama; T. Kiba; A. Subagyo; A. Ikeuchi; K. Sueoka; A. Murayama
  18th International Conference on Dynamical Processes in Excited States of Solids, 06 Aug. 2013, English, Poster presentation
• Optical spin-injection dynamics at excited states in In0.5Ga0.5As quantum dots coupled with an In0.1Ga0.9As quantum well
  X.J. Yang; T. Kiba; Y. Kuno; T. Yamamura; J. Takayama; A. Subagyo; K. Sueoka; A. Murayama
  18th International Conference on Dynamical Processes in Excited States of Solids, 06 Aug. 2013, English, Poster presentation
• Dynamics of electron-spin injection in a heterovalent GaAs/AlGaAs/ZnMnSe structure with a coupled double quantum well of GaAs/AlGaAs
  Y. Kuno; T. Sasaki; T. Kiba; V.Kh. Kaibyshev; F. Liaci; A.A. Toropov; S.V. Ivanov; Akihiro Murayama
  17th International Conference on Molecular Beam Epitaxy, 25 Sep. 2012, English, Poster presentation
• High-density and sub-20-nm GaAs nanodisk array fabricated using neutral beam etching process for high performance QDs devices
  Y. Tamura; M. Igarashi; M.E. Fauzi; R. Tsukamoto; T. Kaizu; T. Kiba; I. Yamashita; Y. Okada; A. Murayama; S. Samukawa
  12th International Conference on Nanotechnology, 22 Aug. 2012, English, Poster presentation
• Picosecond carrier dynamics induced by coupling of wavefunctions in a Si-nanodisk array fabricated by neutral beam etching using bio-nano-templates
  T. Kiba; Y. Mizushima; M. Igarashi; S. Samukawa; A. Murayama
  International Conference on Superlattices, Nanostructures, and Nanodevices, 26 Jul. 2012, English, Poster presentation
• Plasmonic enhancement of photoluminescence in hybrid Si nanostructures with Au fabricated by fully top-down lithography
  K. Nakaji; H. Lee; T. Kiba; M. Igarashi; S. Samukawa; A. Murayama
  International Conference on Superlattices, Nanostructures, and Nanodevices, 24 Jul. 2012, English, Poster presentation
• Fabrication of Two-dimensional Array of Sub-10nm GaAs Nanodisk using Bio-template Neutral Beam Etching Process
  S.H. Lin; M. Igarashi; X.Y. Wang; C.H. Huang; Y. Ohno; A. Murayama; S. Samukawa
  American Vacuum Society 58th International Symposium, 31 Oct. 2011, English, Poster presentation
• High-density optical spin injection in self-assembled semiconductor quantum dots
  A. Murayama; N. Tamura; T. Yamazaki; T. Kiba
  16th International Conference on Luminescence and Optical Spectroscopy of Condensed Matter, 30 Jun. 2011, English, Oral presentation
• Inter-disk electron transfer in Si-nanodisk arrays fabricated by using bio-templates
  T. Kiba; Y. Mizushima; A. Murayama; M. Igarashi; C.-H. Huang; S. Samukawa
  16th International Conference on Luminescence and Optical Spectroscopy of Condensed Matter, 28 Jun. 2011, English, Poster presentation
• Damage-free top-down processes of fabricating two-dimensional array of sub-10nm nanometer GaAs nanodisks using bio-template and neutral beam etching for intermediate band solar cell applications
  X.Y. Wang; C.H. Huang; R. Tsukamoto; T. Kaizu; M. Igarashi; P.A. Mortemousque; H. Shinohara; Y. Okada; A. Murayama; K. Itoh; Y. Ohno; I. Yamashita; S. Samukawa
  37th IEEE Photovoltaic Specialists Conference, 23 Jun. 2011, English, Poster presentation
• Optical absorption, photoluminescence and miniband formation of a highly ordered and dense 2-dimensional array of Si nanodisks for quantum dot solar cells
  M. Igarashi; C.H. Huang; X.Y. Wang; M.F. Budiman; Y. Tamura; T. Kiba; A. Murayama; T. Kaizu; Y. Okada; S. Samukawa
  37th IEEE Photovoltaic Specialists Conference, 24 Jun. 2010, English, Poster presentation
• Surface/interface-related optical properties in Si nanodisks fabricated by neutral-beam etching using bio-templates
  T. Kiba; K. Suzaki; H. Li; M. Igarashi; S. Samukawa; A. Murayama
  17th International Conference on Molecular Beam Epitaxy, 27 Sep. 2009, English, Poster presentation
• 〔Major achievements〕Magnetic semiconductor nanostructures; toward spin manipulation in semiconductor quantum structures
  Akihiro Murayama
  International Workshop on Photons and Spins in Nanostructures, 27 Jul. 2009, English, Invited oral presentation
  [Invited]
• Carrier and spin injection from ZnMnSe to CdSe quantum dots
  D.Dagnelund; I.A. Buyanova; T. Furuta; K. Hyomi; I. Suoma; A. Murayama; W.M. Chen
  3rd. International Conference on Quantum, Nano and Micro Technologies, English, Poster presentation
  01 Feb. 2009 - 07 Feb. 2009
• Spin dynamics in ZnO-based materials
  W.M. Chen; I.A. Buyanova; T. Furuta; A. Murayama; D. P. Norton; S.J. Pearton; A. Osinsky; J. W. Dong
  5th International Conference on Physics and Applications of Spin-related Phenomena in Semiconductors, English, Oral presentation
  03 Aug. 2008 - 06 Aug. 2008
• Micro-photoluminescence study of electron-spin injection in self-assembled semiconductor quantum dots
  K. Hyomi; M. Sakuma; A. Murayama
  15th International Conference on Luminescence and Optical Spectroscopy of Condensed Matter, English, Poster presentation
  07 Jul. 2008 - 11 Jul. 2008
• Transient magneto-photoluminescence in self-assembled quantum dots of a diluted magnetic semiconductor
  S. Oshino; T. Furuta; I. Souma; A. Murayama; D. Dagnelund; I.A. Buyanova; W.M. Chen
  15th International Conference on Luminescence and Optical Spectroscopy of Condensed Matter, English, Poster presentation
  07 Jul. 2008 - 11 Jul. 2008
• Transfer dynamics of spin-polarized excitons into semiconductor quantum dots
  A. Murayama; T. Furuta; S. Oshino; K. Hyomi; M. Sakuma; I. Souma; D. Dagnelund; I.A. Buyanova; W.M. Chen
  15th International Conference on Luminescence and Optical Spectroscopy of Condensed Matter, English, Oral presentation
  07 Jul. 2008 - 11 Jul. 2008
• Cooling and spin-relaxation dynamics of spin-polarized excitons in a diluted magnetic semiconductor quantum well
  A. Murayama; K. Saito; I. Souma
  8th International Conference on Excitonic Processes in Condensed Matter, English, Poster presentation
  22 Jun. 2008 - 27 Jun. 2008
• Propagation dynamics of exciton spins in a high-density semiconductor quantum dot system
  A. Murayama; T. Furuta; S. Oshino; K. Hyomi; M. Sakuma; I. Souma; D. Dagnelund; I.A. Buyanova; W.M. Chen
  8th International Conference on Excitonic Processes in Condensed Matter, English, Oral presentation
  22 Jun. 2008 - 27 Jun. 2008
• Magneto-optical spectroscopy of spin injection from ZnMnSe to CdSe quantum dots
  D. Dagnelund; I. A Buyanova; W.M. Chen; T. Furuta; K. Hyomi; I. Souma; A. Murayama
  The International Scanning Probe Microscopy Conference, English, Poster presentation
  22 Jun. 2008 - 24 Jun. 2008
• Spin injection and spin detection in semiconductor quantum structures
  W.M. Chen; I.A. Buyanova; A. Murayama; Y. Oka; S.J. Pearton; D. P. Norton; C.R. Abernathy; A. Osinsky; J. W. Dong
  The First Nordic Workshop on Spintronics and Nanomagnetism, English, Invited oral presentation
  22 Apr. 2008 - 24 Apr. 2008, [Invited]
• Magneto-optical properties and spin dynamics in novel II-VI and III-V semiconductor materials and nanostructures
  I.A. Buyanova; W.M. Chen; A. Murayama; Y. Oka; C.R. Abernathy; S.J. Pearton
  The Progress in Electromagnetics Research Symposium, English, Invited oral presentation
  24 Mar. 2008 - 28 Mar. 2008, [Invited]

• 集積プロセス学特論, 2024年, 修士課程, 情報科学院
• 集積プロセス学特論, 2024年, 博士後期課程, 情報科学研究科
• 集積プロセス学特論, 2024年, 博士後期課程, 情報科学院
• 物性工学, 2024年, 学士課程, 工学部
• 電気電子工学演習Ⅰ, 2024年, 学士課程, 工学部

• 応用物理学会

• 0-2Dハイブリッド半導体光電スピンインターフェース
  先端的カーボンニュートラル技術開発（ALCA-Next）
  Nov. 2023 - Mar. 2027
  国立研究開発法人科学技術振興機構, 北海道大学, Principal investigator, 23836248
• Semiconductor-based room temperature optical spintronics using novel spin-optical devices
  Grants-in-Aid for Scientific Research
  Apr. 2023 - Mar. 2026
  村山 明宏
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 23H01459
• Optical spin-functional transistor
  Grants-in-Aid for Scientific Research Challenging Research (Pioneering)
  28 Jun. 2019 - 31 Mar. 2024
  村山 明宏
  Japan Society for the Promotion of Science, Challenging Research (Pioneering), Hokkaido University, 20K20433
• 半導体・酸化物複合ナノワイヤによる光・電子・スピン工学の融合
  科学研究費助成事業 基盤研究(A)
  01 Apr. 2019 - 31 Mar. 2023
  石川 史太郎; 村山 明宏; 長島 一樹
  日本学術振興会, 基盤研究(A), 愛媛大学, 19H00855
• Photoelectric conversion system of spin-information utilizing semiconductor quantum dots
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)
  31 May 2016 - 31 Mar. 2021
  村山 明宏; 寒川 誠二; 末岡 和久
  低消費電力光デバイス実用材料であるIII-V 族化合物半導体量子ドットでは、電子のスピン緩和時間が発光寿命より十分長く、量子ドットに注入された電子のスピン状態は光電変換により発光の円偏光特性に変換される。そこで、室温動作可能な強磁性体電極から電子スピンを高効率に電流輸送するため、量子ドットへの超高速スピン注入および半導体バリア中のスピン輸送を研究し、量子ドットを用いた光電スピン情報変換システムの基盤を構築していく。交付申請書の研究計画に沿って得られた本年度の実績を以下にまとめる。
  積層デバイス構造中の点状の量子ドットに対してスピン偏極電子を高速で捕獲し注入するため、二次元量子井戸に量子ドットを結合させた独自のスピン注入型エピタキシャル構造からなる光電スピン変換活性層の研究を推進した。まず、井戸ポテンシャルを介するドット間結合により励起状態のスピン偏強度を増幅し発光再結合中に維持した。また、ドットに注入された電子のエネルギー緩和過程を研究し、2種類の光学フォノン散乱が共鳴しスピン偏極が高く保たれるスピンフォノンボトルネックが存在することを示した。そこで電界効果素子を作製し、井戸とドットの次元性の異なるトンネルスピン結合に光学フォノンが共鳴散乱する極めて高効率のフォノン共鳴スピン注入を実現した。さらに、スピン注入に対する電界依存性を研究し、発光の円偏光特性すなわち注入電子スピンの偏極を電界で制御・反転できる素子を考案した。
  半導体バリアのスピン輸送に関してはAlGaAs/GaAs超格子バリアの研究を進め、超格子の構造を最適化することによりスピン緩和を抑制した量子波による長距離スピン輸送が可能であることを示した。スピン緩和を抑えるスピン輸送チャネルや円偏光増幅を目指すバリアのナノ加工、金属強磁性体電極を用いるスピン注入型発光ダイオードの作製などの光機能スピン素子の研究も進めている。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Hokkaido University, 16H06359
• 二次元電子系と結合した量子ドットスピン状態の電界操作による動的スピン制御
  科学研究費助成事業 基盤研究(A)
  01 Apr. 2016 - 31 Mar. 2019
  村山 明宏
  日本学術振興会, 基盤研究(A), 北海道大学, 16H02101
• Aharonov-Bohm effect in optically functional Type-I semiconductor quantum structures
  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
  01 Apr. 2015 - 31 Mar. 2017
  Murayama Akihiro
  We study the Aharonov-Bohm (AB) effect, that is an interference phenomenon caused by coherent phase difference of electron- and hole-wavefunctions, in Type-I semiconductor quantum dots (QDs) suitable for optical device applications. Optical detection of the AB effect has been limited to core-shell type-II QDs so far. Therefore, we aimed to obtain knowledge about the AB effect in the Type-I QDs by using quantum ring samples combining type-I GaAs QDs grown by droplet epitaxy, utilizing the one-dimensional nature of the wavefunctions in the ring direction. Magnetic-field dependences of the emission spectrum from a single quantum ring are measured by micro-photoluminescence spectroscopy under magnetic fields up to 5 T, and investigations are conducted in consideration of the Zeeman shift induced by the magnetic field.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 15K13267
• Spin-polarized Lasing in Quantum Dots
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)
  01 Apr. 2010 - 31 Mar. 2015
  MURAYAMA Akihiro; SUEOKA Kazuhisa; SUGAWARA Hirotake
  We have studied spin-polarized lasing, which can transform electron-spin information into circular polarization properties in stimulated emission, by employing III-V compound semiconductor quantum dots (QDs) exhibiting strong suppression of spin relaxation.
  Spin-injection dynamics and spin relaxation in QDs in addition to fabrication processes of QDs have been studied for the purpose of temporal spin storage during the emission. We show that Pauli spin blocking is a major factor of spin loss during the spin injection into QDs. To resolve this issue, we conclude that high density QDs and tunneling of spins from two-dimensional electron systems realize highly efficient and ultrafast spin injection into QDs. QD light emitting diodes with active layers composed of QDs and metallic ferromagnetic spin electrodes have been fabricated, which indicates circularly polarized electroluminescence reflecting efficient electron-spin injection.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Hokkaido University, 22221007
• Optically functional hybrid quantum dots
  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
  2011 - 2013
  MURAYAMA Akihiro
  Plasmonic effects induced by Au nano-particles in semiconductor quantum dots (QDs) were studied, aiming at efficient coupling between carriers in the QDs and lights. Various optically functional hybrid QDs with Au nano-particles were artificially fabricated, where the distance between the QD and the Au nano-particle was intentionally controlled by using modified molecular chains or nano-lithography techniques based on the protein engineering. In Si QDs, enhancements of the photoluminescence (PL) intensity originating from the localized plasmonic effect were observed. However, in II-VI or III-V QDs with high internal quantum efficiencies, PL intensities significantly decrease because of the energy transfer from the excited states in the QDs into the Au nano-particles, rather than the plasmonic enhancement effect.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 23656002
• 半導体量子ドットネットワークにおけるスピン情報伝搬ダイナミクス
  科学研究費助成事業 挑戦的萌芽研究
  2008 - 2010
  村山 明宏
  研究実施計画にしたがい、平成21年に引き続き本年度は以下の研究を実施した。
  (1)自己組織化量子ドットと希薄磁性半導体結合構造の微細加工
  自己組織化量子ドットと希薄磁性半導体の結合構造を利用して、希薄磁性半導体に光生成した電子・励起子スピンを量子ドット集合体の特定位置に注入するため、電子ビームリソグラフィーにより希薄磁性半導体層の微細加工を行った。その結果、直径200nm程度のメサ構造を作製することができた。さらに、このような自己組織化量子ドットと希薄磁性半導体の結合ナノ構造に対して、磁場中での円偏光顕微発光分光を行い、特定の量子ドット集合体における高い円偏光度を持つ発光スペクトルを観測し、そのスピン注入現象を確認することができた。
  (2)自己組織化量子ドットへのスピン注入と量子ドット間スピン伝搬ダイナミクスの分光計測
  希薄磁性半導体と結合した量子ドットに対して、円偏光を用いたピコ秒時間分解発光分光により、量子ドットへのスピン注入を示す発光とその円偏光度の時間変化、およびその詳細な励起子エネルギー依存性や励起密度依存性、さらに温度依存性などを測定した。このような測定結果に対して、スピン伝搬ダイナミクスとドット内スピン緩和時定数を取り込んだレート方程式解析を行い、注入されたスピンのドット間伝搬ダイナミクスとドット内スピン緩和ダイナミクスについて明らかにした。その結果、低温領域において主としてトンネル過程によりスピン偏極キャリアが伝搬する場合、スピン緩和は量子ドット内におけるスピン緩和過程に支配される。これに対して、温度が上がってくると、各量子ドット内に局在しているスピンが熱励起されるためドット間を拡散し、このような拡散過程におけるスピン緩和が顕著となる。
  日本学術振興会, 挑戦的萌芽研究, 北海道大学, 20656001
• Fabrication of magnetic hybrid structures of semiconductor quantum dots and the spin-functional optical properties
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2007 - 2009
  MURAYAMA Akihiro
  Magnetic hybrid structures of semiconductor quantum dots (QDs) with diluted magnetic semiconductors (DMSs), indicating giant magneto-optical properties, were fabricated. Spin-polarized electrons were optically generated in the DMS and were subsequently transferred into non-magnetic QDs via quantum tunneling (spin injection). The spin states of the electrons were temporally conserved in the QDs and were also read-out by circularly polarized photoluminescence.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), 19360001
• Optical Control of Electron Spins in Hybrid Quantum Structures of Diluted Magnetic Semiconductors
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2005 - 2006
  OKA Yasuo; MURAYAMA Akihiro
  The objective of the research program is following:
  1.Designing and fabrication of new hybrid nanostructures composed of II-VI compound diluted magnetic semiconductors and magnetic metals.
  2.Study of optical spin injection and spin relaxation in the hybrid nanostructures of quantum dots and quantum wells for the application on spin electronic devices.
  We have fabricated, for the above objectives, the quantum structures and hybrid nanostructures with CdTe,CdSe,ZnTe,ZnSe and magnetic materials of Mn and Co by using molecular expitaxy and electron beam lithography. Fabricated quantum nanostructures are studied by femtosecond laser spectroscopy by applying high magnetic fields. Spin injection processes of electrons, holes and excitons are investigated in the quantum wells and quantum dots of ZnMnSe-ZnSe,CdMnSe-CdSe and CdMnTe-CdTe systems. Transient photoluminescence of excitons shows fast spin injection and spin relaxation processes in the quantum structures induced by the magnetic field. Ultrafast spin dynamics of carriers is investigated in the diluted magnetic double quantum wells by transient pump-probe spectroscopy. The spin injection dynamics of electrons and holes are clarified in femtosecond time domain. Hybrid nanostructures with the diluted magnetic semiconductors and the magnetic metals were fabricated by electron beam lithography technique. The diluted magnetic quantum disks in the hybrid structures show the Zeeman splitting without applying external magnetic field, which verifies the affection the ferromagnetic nano-scale magnets neighboring to the quantum disks. The obtained results in the present research have high possibilities for spin electronic applications.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tohoku University, 17340090
• 磁性体・半導体ハイブリッド構造によるナノスピンの生成と制御
  科学研究費助成事業 特定領域研究
  2004 - 2005
  村山 明宏; 岡 泰夫; 西林 一彦
  本研究においては、化合物磁性半導体の原子層制御エピタキシャル量子井戸・規則配列量子ドット・自己組織化量子ドット等の各種ナノ量子構造を作製する。また、Co系合金などの金属強磁性体、あるいは半導体結晶とエピタキシャル成長するMn系化合物磁性体を接合あるいは組み合わせた、新しい磁性体・半導体ハイブリッドナノ構造を創出する。そして、このような磁性体・半導体ハイブリッドナノ構造のスピン光物性を調べるとともに、半導体のスピン秩序を磁性体により制御することを試みる。
  特に本年度は、これまでの研究成果である磁性半導体と非磁性半導体のナノ構造作成技術を生かして、非磁性半導体CdSe自己組織化量子ドットと磁性半導体ZnCdMnSe量子井戸をトンネル結合させた全く新しい光スピン機能性量子ナノ構造を創製した。その結果、磁性半導体において光生成したスピン偏極電子を、共鳴トンネル効果により超高速かつ高効率に自己組織化量子ドットに注入することに成功した。
  さらに、電子ビームリソグラフィーにより作製した垂直磁化Co/Pt多層膜と磁性半導体ZnCdMnSe量子井戸の複合ナノディスク構造を考案・作製した。ZnCdMnSeナノディスクの励起子発光の円偏光特性を調べ、Co垂直磁化より半導体ナノディスクに生じる局所的な垂直磁場により誘導される励起子巨大ゼーマン効果の発現を明らかにした。すなわち、強磁性体ナノ構造から生じる磁場を利用して、半導体励起子キャリアのスピン状態を制御することに成功した。
  また、磁場中円偏光ポンププローブ分光により、磁性半導体CdMgMnTeと非磁性半導体CdTe量子井戸をトンネル結合させた磁性結合二重量子井戸におけるキャリアスピンダイナミクスを研究した。その結果、磁性井戸において光生成したスピン偏極電子・正孔は、個別トンネルにより非磁性井戸へ輸送されることを示した。
  日本学術振興会, 特定領域研究, 東北大学, 16031201
• Magnetic properties and optical spin functionalities of atomically layer-controlled hybrid structures of semiconductors with magnetic materials
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2003 - 2005
  MURAYAMA Akihiro; NISHIBAYASHI Kazuhiro
  In this research, atomically layer-controlled hybrid structures of semiconductors with magnetic materials are fabricated. It has aimed to research microscopic magnetic interactions at the interfaces and magneto-optical functionalities in these nanostructures, and to develop hybrid nano-materials exhibiting new optical spin functionalities. The following results are obtained.
  (1) ZnCdSe quantum wells were epitaxially grown with magnetic delta-doping of antiferromagnetic MnSe atomic layers. The magnetic spins of such an atomically layer-controlled ultra-thin film were studied and the correlation with excitons was clarified.
  (2) Hybrid nanostructures of ZnCdMnSe quantum wells with Co wires were developed by electron-beam lithography. Light scattering were observed due to the ferromagnetic spin waves in Co and the spin flip of the Mn ion. As a result, the local effective magnetic-field-distribution from the Co was quantified in such a magnetic hybrid nanostructure.
  (3) Magnetic asymmetric double quantum wells were fabricated, where non-magnetic semiconductor ZnCdSe and magnetic semiconductor ZnCdMnSe quantum wells were coupled, and the excitonic spin dynamics was studied by circularly polarized time-resolved PL in magnetic fields. It was observed that the type-II transition was induced by the magnetic field depending on the spin. This realizes a new optical spin functionality to separate spatially the hole spins.
  (4) Hybrid nano-disk structures of magnetic semiconductor ZnCdMnSe quantum wells with perpendicular magnetic Co/Pt multilayers were newly developed by an electron-beam lithography technique. It succeeded in the control of excitonic spin state in the semiconductor nano-disks by the local perpendicular magnetic fields generated from the perpendicular Co magnetization.
  (5) A optical spin functionality was developed in hybrid quantum nanostructures of CdSe Self-assembled quantum dots with magnetic semiconductor ZnCdMnSe quantum wells with tunnel barriers.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), TOHOKU UNIVERSITY, 15360002
• Optical Spin Injection and Carrier Transport in Hybrid Nanostructures of Semiconductors and Magnetic Metals
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  2001 - 2003
  OKA Yasuo; NISHIBAYASHI Kazuhiro; TOMITA Takuro; MURAYAMA Akihiro
  The objective of the research is following:
  1.Fabrication of hybrid nanostrctures of quantum wires, quantum dots and quantum wells, which are composed of II-VI compound diluted magnetic semiconductors and magnetic metals.
  2.Study of optical spin injection and spin transport in the hybrid nanostructures and application for spin electronic devices. For the above objective, we have fabricated the quantum nanostructures and hybrid nanostructures with CdTe, CdSe, ZnTe, ZuSe and magnetic materials of Mn and Co by using molecular expitaxy and electron beam lithography methods. Fabricated quantum and hybrid nanostructures are studied by femtosecond laser spectroscopy in high magnetic fields. Spin injection processes are investigated in CdTe-CdMnTe double quantum wells, where the transient photoluminescence of quantum-well excitons shows that spin injection and spin relaxation processes. Spin switching processes are clarified in ZnTe-ZnMnTe spin superlattices, where the distribution of up-and down-spin states of excitons is spatially separated in Zute and ZnMnTe layers by the external magnetic fields. The lowest spin state of excitons is modified from that of the ZnTe layer to that of the ZuMnTe due to the large Zeeman splitting of the exciton spins in the ZnMnTe layer. From the transient characteristics of the exciton photoluminescence, the reverse spin injection process (spin switching) is confirmed and the spin injection times are determined. Ultrafast spin dynamics of excitons is investigated in these diluted magnetic nanostructures by transient pump-probe spectroscopy. The spin dynamics in the high density electron-hole plasma, excitons, and Mn ions are clarified in the femotsecond to nanosecond time region. Fabrication of hybrid nanostructures is made by using electron beam lithography technique. The diluted magnetic quantum wells in the hybrid structures are affected by the magnetic field, which is induced by the ferromagnetic Co wires neighboring to the quantum wells. These phenomena have high possibilities for spin electronic applications.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tohoku University, 13450002
• Fabrication and Study of Nanostructure Diluted Magnetic Semiconductors
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
  1996 - 1998
  OKA Yasuo; MURAYAMA Akihiro; TAKAHASI Masaaki; YANATA Kohei; SHEN J.X.
  The objective of this research project is to fabricate new nanostructure lattices composed of diluted magnetic semiconductors (DMSs) and also to study magneto-optical properties of the nanostructures. For this purposes, we have fabricated 2-dimensional quantum wells, 1-dimensional quantum wires, and 0-dimensional quantum dots by molecular beam epitaxy, atomic beam epitaxy, and electron-beam lithography techniques. Materials we have fabricated are Cd_<1-x>Mn_xTe and Cd_<1-x>Mn_xSe with Mn concentration of x= 0.03-0.3.
  Obtained these nanostructures have been studied by the ultrafast laser spectroscopy using femto-second pulse lasers. Time resolved photoluminescence has been measured in Cd_<1-x>Mn_xTe quantum wells by the selective excitation of the quantum-well exciton states. The transient behavior of the exciton luminescence clearly shows the formation process of the excitonic magnetic polarons, which is suppressed by the strong external magnetic fields. Quantum dots of Cd_<1-x>Mn_xSe grown by the Stranski-Krastanow mode on ZnSe buffer layers show very fast decay of the excitons in the dots. The lifetime of the quantum dot excitons is markedly increased by the external magnetic fields. The phenomena are interpreted by decrease of the nonradiative process due to the shrinkage of the exciton wavefunction by the magnetic field. Pump-probe transient absorption spectroscopy has been made on Cd_<1-x>Mn_xTe quantum well, The exciton and magnetic polaron dynamics are observed in the 2 ps to 3 ns time region. Quantum wires of Zn_<1-x>Cd_xSe system show the photoluminescence evidence of the 1-dimensional confinement effect as well as the relaxation of the lattice strains by decreasing the wire width. Fabrication of Cd_<1-x>Mn_xSe quantum wires is under progress.
  The remarkable magneto-optical effects of the nanaostructure DMSs elucidated in the present project will stimulate the research of the new magneto-optical microdevices.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Research Institute for Scientific Measurements, Tohoku University, 08555001