1999 Fiscal Year Annual Research Report

スピン制御された半導体超構造の電子物性と応用

Research Project

Project/Area Number	09244103
Research Institution	Tohoku University
Principal Investigator	大野英男東北大学, 電気通信研究所, 教授 (00152215)
Co-Investigator(Kenkyū-buntansha)	樽茶清悟東京大学, 理学研究科, 教授 (40302799) 鈴木直大阪大学, 大学院・基礎工学研究科, 教授 (40029559) 勝本信吾東京大学, 物性研究所, 助教授 (10185829)
Keywords	(非)磁性半導体 / (Ga,Mn)As / アニール効果 / kp摂動 / 第一原理計算 / スピン注入 / スピン緩和 / 人工分子
Research Abstract	本年度は磁性半導体・非磁性半導体及びそれらの超構造について、輸送測定を中心にスピンにまつわる物性の観測と制御とその解明を行った。磁性半導体に対して実験的に、1.パーセント・オーダのMnを導入したGaSbの磁気的性質及び磁気輸送特性の結晶成長温度依存性を調べ、閃亜鉛構造の強磁性(Ga,Mn)Sbを形成するMnの量は低温成長することにより増えることを明らかにした、2.強磁性半導体(Ga,Mn)As及び(In,Mn)Asを結晶成長後に低温でアニールすることにより、電気伝導の向上や磁気転移温度の向上が起こることを示した。また理論的に、1.磁化と歪みを加味したk・p摂動法により(Ga,Mn)As価電子帯構造を計算し、強磁性転移温度と磁気異方性の実験結果を定量的に再現できることを示した、2.第一原理電子状態計算により新しい材料である(Ga,Cr)Asが非常に高い転移温度を持つ強磁性体になり得ることを示した。またそれらのヘテロ構造に対して実験的に、1.(Ga,Mn)As/(Al,Ga)As/(Ga,Mn)As三層構造においてスピン依存散乱による磁気抵抗効果を確認し、磁気抵抗比と(GaMn)As層間の磁気的結合の大きさを中間比磁性層のAl組成と温度により制御できることを示した、2.(Ga,Mn)Asをベースとする強磁性/非磁性半導体ヘテロ接合において、スピン偏極電流注入を発光偏光測定により直接明らかにした。また理論的に、l.k・p摂動法により計算した(Ga,Mn)As価電子帯構造を用い(Ga,Mn)Asをエミッタとして用い共鳴トンネル・ダイオード構造の電流-電圧特性の振る舞いを計算し実験結果を定性的に再現した。非磁性半導体に対して、1.GaAs/(Al,Ga)As量子井戸のスピン緩和時間を調べ、井戸の面方位やドーピングを適切に制御することにより室温で10ns以上までスピン緩和時間を延長できることを明らかにした、2.縦型二重量子ドット(人工分子)において、ゼロ磁場での非線形コンダクタンスを測定し、電子数2のクーロンブロッケード領域の近傍でスピン選択則に起因するブロッケード領域を観察し、この領域内での2電子スピンは三重項状態であることを見いだした。

Research Products

(39 results)

All Other

All Publications (39 results)

[Publications] T.Dietl: "Zener Model Description of Ferromagnetism in Zinc-Blende Magnetic Semiconductors"Science. 287. 1019-1022 (2000)
[Publications] Y.Ohno: "Electrical spin injection in a ferromagnetic smiconductor heterostructure"Nature. 402. 790-792 (1999)
[Publications] Y.Ohno: "Spin relaxation in GaAs(110) quantum wells"Physical Review Letters. 83. 4196-4199 (1999)
[Publications] H.Ohno: "Preperties of ferromagnetic III-V semiconductors"Journal of Magnetism and Magnetic Meterials. 200. 110-129 (1999)
[Publications] H.Ohno: "III-V based ferromagnetic semiconductors"Jounal of Magnetic Society of Japan. 23. 88-92 (1999)
[Publications] F.Matsukura: "Magnetotransport properties of (Ga,Mn)As/(Al,Ga)As/(Ga,Mn)As trilayer structures"Jounal of Magnetic Society of Japan. 23. 99-101 (1999)
[Publications] A.Oiwa: "Magnetic and transport properties of the ferromagnetic semiconductor heterostructures (In,Mn)As/(Al,Ga)Sb"Physical Review B. 59・8. 5826-5831 (1999)
[Publications] K.Ohtani: "Intersubband electroluminescence in InAs/GaSb/AlSb type-II cascade structures"Applied Physics Letters. 74・10. 1409-1411 (1999)
[Publications] Ryota Terauchi: "Carrier mobility dependence of electron spin relaxation in GaAs quantum wells"Japanese Journal of Applied Physics. 74・10. 1409-1411 (1999)
[Publications] H.Ohno: "Spin-dependent tunneling and properties of ferromagnetic (Ga,Mn)As(invited)"Journal of Applied Physics. 85・8. 4277-4282 (1999)
[Publications] J.Szczytko: "Antiferromagnetic p-d exchange in ferromagnetic Ga_<1-x>Mn_xAs epilayers"Physical Review B. 59・20. 12395-12939 (1999)
[Publications] Y.Iye: "Metal-insulator transition and magnetotransport in III-V compound diluted magnetic semiconductors"Materials Science and Engineering B. 63. 88-95 (1999)
[Publications] A.Shen: "Low-temperature molecular beam epitaxial growth of GaAs and (Ga,Mn)As"Journal of Crystal Growth. 201/202. 679-683 (1999)
[Publications] S.P.Guo: "InAs and (In,Mn)As nanostructures grown on GaAs (110), (211)B and (311)B substrates"Journal of Crystal Growth. 201/202. 684-688 (1999)
[Publications] A.Sato: "X-ray diffraction study of InAs/AlSb interface bonds growth by molecular beam epitaxy"Journal of Crystal Growth. 201/202. 861-863 (1999)
[Publications] Haruyuki Yasuda: "Monte Carlo simulation of reentrant reflection high-energy electron diffraction intensity oscillation observed during low-temperature GaAs growth"Applied Physics Letters. 74・22. 3275-3277 (1999)
[Publications] A.Sawada: "Interlayer coherence in v=1 and v=2 bilayer quantum Hall states"Physical Review B. 59・23. 14888-14891 (1999)
[Publications] T.Wang: "Electron mobility exceeding 10^4 cm^2/Vs in AlGaN-GaN heterostructures growtn on sapphire substrate"Applied Physics Letters. 74・23. 3531-3533 (1999)
[Publications] F.Matsukura: "Properties of (Ga,Mn)As and their dependence on molecular beam growth conditions"Inst. Phys/Conf. Ser.. 162. 547-552 (1999)
[Publications] H.Ohno: "Ferromagnetic III-V semiconductors and their heterostructures"Proc. of the 24th Intl. Conf. on the Physics of semiconductors. 139-146 (1999)
[Publications] J.G.E.Harris: "Integrated michromechanical cantilever magnetomrtory of Ga_<1-x>Mn_xAs"Applied Physics Letters. 75・8. 1140-1142 (1999)
[Publications] B.Beshoten: "Magnetic Circular Dochorism Studies of Carrier-Induced Ferromagnetism in (Ga_<1-x>Mn_x)As"Physical Review Letters. 85・15. 3073-3076 (1999)
[Publications] S.P.Guo: "Surfactant effect of Mn on the formation of self-organized InAs nonostructures"Journal of Crysta Growth. 208. 799-803 (2000)
[Publications] Y.Ohno: "Electron Spin Relaxation Beyond D' yakonov-Perel' Interaction in Ga/As/AlGaAs Quantum Wells"Physica E. (in press). (2000)
[Publications] T.Dietl: "Ferromagnetism in III-V and II-VI semiconductor structures"Physica E. (in press). (2000)
[Publications] T.Dietl: "Ferromagnetism induced by free carriers in p-type structures of diluted magnetic semiconductors"Physica E. (in press). (2000)
[Publications] T.Omiya: "Magnetotransport properties of (Ga,Mn)As investigated at low temperature and high magnetic field"Physica E. (in press). (2000)
[Publications] T.Adachi: "Mobility dependence of electron spin relaxation tume in n-type InGaAs/InAlAs multiple quantum wells"Physica E. (in press). (2000)
[Publications] K.Ohtani: "Mid-infrared intersubband electroluminescence in InAs/GaSb/AlSb type-II cascade structure"Physica E. (in press). (2000)
[Publications] E.Abe: "Molecular Beam Epitaxy of III-V Diluted Magnetic Semiconductor (Ga,Mn)Sb"Physica E. (in press). (2000)
[Publications] Y.Ohno: "MBE growth of hybrid ferromagnetic/non-magnetic semiconductor ; pn junctions based on (Ga,Mn)As"Applied Surface Science. (in press). (2000)
[Publications] F.Matsukura: "Molecular beam epitaxy of GaSb with high eoncentration of Mn"Applied Surface Science. (in press). (2000)
[Publications] K.Ohtani: "Influence of Interface bond and buffer material on the optical properties of InAs/AlSb quantum wells grown on GaAs substrates"Applied Surface Science. (in press). (2000)
[Publications] F.Matsukura: "Magnetotransport properties of (Ga,Mn)Sb"Journal of Applied Physics. (in press). (2000)
[Publications] N.Akiba: "Spin-dependent transport in semiconducting ferromagnetic (Ga,Mn)As trilayer structure"Journal of Applied Physics. (in press). (2000)
[Publications] H.Ohldag: "Magnetic moment of Mn in the ferromagnetic semiconductor (Ga_<0.98>Mn_<0.02>)As"Applied Physics Letters. (in press). (2000)
[Publications] T.Ogawa: "First-principles caluculations of electronic structures of diluted magnetic semiconductors (Ga,Mn)As"Journal of Magnetism and Magnetic Materials. 196-197. 428-429 (1999)
[Publications] M.Shirai: "First-principles electronic structure calculations of MnAs/GaAs(001) magnetic multilayers"Japanese Journal of Applied Physics Suppl.. 38-1. 423-424 (1999)
[Publications] D.G.Austing: "Quantum Dot Molecules"Physica B. 249-251. 206-209+ (2000)

1999 Fiscal Year Annual Research Report

スピン制御された半導体超構造の電子物性と応用

Principal Investigator

大野 英男 東北大学, 電気通信研究所, 教授 (00152215)

Research Products

[Publications] T.Dietl: "Zener Model Description of Ferromagnetism in Zinc-Blende Magnetic Semiconductors"Science. 287. 1019-1022 (2000)

[Publications] Y.Ohno: "Electrical spin injection in a ferromagnetic smiconductor heterostructure"Nature. 402. 790-792 (1999)

[Publications] Y.Ohno: "Spin relaxation in GaAs(110) quantum wells"Physical Review Letters. 83. 4196-4199 (1999)

[Publications] H.Ohno: "Preperties of ferromagnetic III-V semiconductors"Journal of Magnetism and Magnetic Meterials. 200. 110-129 (1999)

[Publications] H.Ohno: "III-V based ferromagnetic semiconductors"Jounal of Magnetic Society of Japan. 23. 88-92 (1999)

[Publications] F.Matsukura: "Magnetotransport properties of (Ga,Mn)As/(Al,Ga)As/(Ga,Mn)As trilayer structures"Jounal of Magnetic Society of Japan. 23. 99-101 (1999)

[Publications] A.Oiwa: "Magnetic and transport properties of the ferromagnetic semiconductor heterostructures (In,Mn)As/(Al,Ga)Sb"Physical Review B. 59・8. 5826-5831 (1999)

[Publications] K.Ohtani: "Intersubband electroluminescence in InAs/GaSb/AlSb type-II cascade structures"Applied Physics Letters. 74・10. 1409-1411 (1999)

[Publications] Ryota Terauchi: "Carrier mobility dependence of electron spin relaxation in GaAs quantum wells"Japanese Journal of Applied Physics. 74・10. 1409-1411 (1999)

[Publications] H.Ohno: "Spin-dependent tunneling and properties of ferromagnetic (Ga,Mn)As(invited)"Journal of Applied Physics. 85・8. 4277-4282 (1999)

[Publications] J.Szczytko: "Antiferromagnetic p-d exchange in ferromagnetic Ga_<1-x>Mn_xAs epilayers"Physical Review B. 59・20. 12395-12939 (1999)

[Publications] Y.Iye: "Metal-insulator transition and magnetotransport in III-V compound diluted magnetic semiconductors"Materials Science and Engineering B. 63. 88-95 (1999)

[Publications] A.Shen: "Low-temperature molecular beam epitaxial growth of GaAs and (Ga,Mn)As"Journal of Crystal Growth. 201/202. 679-683 (1999)

[Publications] S.P.Guo: "InAs and (In,Mn)As nanostructures grown on GaAs (110), (211)B and (311)B substrates"Journal of Crystal Growth. 201/202. 684-688 (1999)

[Publications] A.Sato: "X-ray diffraction study of InAs/AlSb interface bonds growth by molecular beam epitaxy"Journal of Crystal Growth. 201/202. 861-863 (1999)

[Publications] Haruyuki Yasuda: "Monte Carlo simulation of reentrant reflection high-energy electron diffraction intensity oscillation observed during low-temperature GaAs growth"Applied Physics Letters. 74・22. 3275-3277 (1999)

[Publications] A.Sawada: "Interlayer coherence in v=1 and v=2 bilayer quantum Hall states"Physical Review B. 59・23. 14888-14891 (1999)

[Publications] T.Wang: "Electron mobility exceeding 10^4 cm^2/Vs in AlGaN-GaN heterostructures growtn on sapphire substrate"Applied Physics Letters. 74・23. 3531-3533 (1999)

[Publications] F.Matsukura: "Properties of (Ga,Mn)As and their dependence on molecular beam growth conditions"Inst. Phys/Conf. Ser.. 162. 547-552 (1999)

[Publications] H.Ohno: "Ferromagnetic III-V semiconductors and their heterostructures"Proc. of the 24th Intl. Conf. on the Physics of semiconductors. 139-146 (1999)

[Publications] J.G.E.Harris: "Integrated michromechanical cantilever magnetomrtory of Ga_<1-x>Mn_xAs"Applied Physics Letters. 75・8. 1140-1142 (1999)

[Publications] B.Beshoten: "Magnetic Circular Dochorism Studies of Carrier-Induced Ferromagnetism in (Ga_<1-x>Mn_x)As"Physical Review Letters. 85・15. 3073-3076 (1999)

[Publications] S.P.Guo: "Surfactant effect of Mn on the formation of self-organized InAs nonostructures"Journal of Crysta Growth. 208. 799-803 (2000)

[Publications] Y.Ohno: "Electron Spin Relaxation Beyond D' yakonov-Perel' Interaction in Ga/As/AlGaAs Quantum Wells"Physica E. (in press). (2000)

[Publications] T.Dietl: "Ferromagnetism in III-V and II-VI semiconductor structures"Physica E. (in press). (2000)

[Publications] T.Dietl: "Ferromagnetism induced by free carriers in p-type structures of diluted magnetic semiconductors"Physica E. (in press). (2000)

[Publications] T.Omiya: "Magnetotransport properties of (Ga,Mn)As investigated at low temperature and high magnetic field"Physica E. (in press). (2000)

[Publications] T.Adachi: "Mobility dependence of electron spin relaxation tume in n-type InGaAs/InAlAs multiple quantum wells"Physica E. (in press). (2000)

[Publications] K.Ohtani: "Mid-infrared intersubband electroluminescence in InAs/GaSb/AlSb type-II cascade structure"Physica E. (in press). (2000)

[Publications] E.Abe: "Molecular Beam Epitaxy of III-V Diluted Magnetic Semiconductor (Ga,Mn)Sb"Physica E. (in press). (2000)

[Publications] Y.Ohno: "MBE growth of hybrid ferromagnetic/non-magnetic semiconductor ; pn junctions based on (Ga,Mn)As"Applied Surface Science. (in press). (2000)

[Publications] F.Matsukura: "Molecular beam epitaxy of GaSb with high eoncentration of Mn"Applied Surface Science. (in press). (2000)

[Publications] K.Ohtani: "Influence of Interface bond and buffer material on the optical properties of InAs/AlSb quantum wells grown on GaAs substrates"Applied Surface Science. (in press). (2000)

[Publications] F.Matsukura: "Magnetotransport properties of (Ga,Mn)Sb"Journal of Applied Physics. (in press). (2000)

[Publications] N.Akiba: "Spin-dependent transport in semiconducting ferromagnetic (Ga,Mn)As trilayer structure"Journal of Applied Physics. (in press). (2000)

[Publications] H.Ohldag: "Magnetic moment of Mn in the ferromagnetic semiconductor (Ga_<0.98>Mn_<0.02>)As"Applied Physics Letters. (in press). (2000)

[Publications] T.Ogawa: "First-principles caluculations of electronic structures of diluted magnetic semiconductors (Ga,Mn)As"Journal of Magnetism and Magnetic Materials. 196-197. 428-429 (1999)

[Publications] M.Shirai: "First-principles electronic structure calculations of MnAs/GaAs(001) magnetic multilayers"Japanese Journal of Applied Physics Suppl.. 38-1. 423-424 (1999)

[Publications] D.G.Austing: "Quantum Dot Molecules"Physica B. 249-251. 206-209+ (2000)

大野英男東北大学, 電気通信研究所, 教授 (00152215)