Spin-functional materials and devices using narrow-gap ferromagnetic semiconductors

2017 Fiscal Year Annual Research Report

• Project/Area Number: 16K14224
• Research Institution: The University of Tokyo
• Principal Investigator: 田中 雅明 東京大学, 大学院工学系研究科(工学部), 教授 (30192636)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 狭ギャップ半導体 / 強磁性半導体 / スピン / 電界効果トランジスタ / キャリア誘起強磁性 / キュリー温度 / 電界による磁性制御

Outline of Annual Research Achievements

Fe-AsおよびFe-Sb正四面体構造をもつ狭ギャップIII-V族ベース強磁性半導体とそのスピン機能ヘテロ構造材料の作製、物性機能の探索、デバイス応用の研究を行った。強磁性半導体とは、非磁性半導体に磁性元素を添加した混晶半導体であり、半導体と磁性体の両方の性質を持つため、固体物理学・材料科学上の科学的課題を豊富に与えるとともに次世代スピントロニクス・デバイスを担う材料として期待されている。今年度は以下の研究成果を得た。
1) n型強磁性半導体(In,Fe)Sbを作製し、この材料ではキュリー温度TCが335 Kに達し、室温での異常ホール効果が大きく現在最も感度の良いInSbの正常ホール効果によるセンサーよりも感度が良いセンサーデバイスが作製可能であることを示した。
2) ｎ型強磁性半導体(In,Fe)Sbをチャネルとする電界効果トランジスタ(FET)を作製し、ゲート電界によって電子濃度を変調し、電気的手法でTCを変調できることを示した。これにより、真性の電子誘起強磁性半導体であることが判明した。ただし、電子濃度に依存しない強磁性秩序の寄与もあり、これが近接Fe原子間の強磁性的超交換相互作用である可能性を示した。
3) 本研究によって、ｎ型とｐ型の両方で室温以上のTCをもつIII-V族強磁性半導体を作製できることを示した。強磁性発現機構として、Feのd-準位とホストIII-V族半導体の価電子帯端あるいは伝導帯端のエネルギーが近い時に強磁性が発現しやすくTcも上がるという、「共鳴バンドモデル」がよく当てはまることを示した。これによって半導体における強磁性発現機構の統一的理解に大きく貢献した。

Research Products

• [Journal Article] Electrical tuning of the band alignment and magnetoconductance in an n-type ferromagnetic semiconductor (In,Fe)As-based spin-Esaki diode (2018)
  • Author(s): Anh Le Duc, Hai Pham Nam, Tanaka Masaaki
  • Journal Title: Appl. Phys. Lett. Volume: 112 Pages: 102402～102402
  • DOI: 10.1063/1.5010020
  • Peer Reviewed / Open Access
• [Journal Article] Electrical control of ferromagnetism in the n-type ferromagnetic semiconductor (In,Fe)Sb with high Curie temperature (2018)
  • Author(s): Nguyen Thanh Tu, Pham Nam Hai, Le Duc Anh, and Masaaki Tanaka
  • Journal Title: Appl. Phys. Lett. Volume: 112 Pages: 122409～122409
  • DOI: 10.1063/1.5022828
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] n 型強磁性半導体(In,Fe)As:Be の価電子帯電子構造 (2018)
  • Author(s): 小林正起、Le Duc Anh、Pham Nam Hai、原田慈久、T. Schmitt、藤森淳、田中雅明、尾嶋正治、V. N. Strocov
  • Organizer: 応用物理学会新領域グループ「強的秩序とその操作に関わる研究グループ」第6回研究会
• [Presentation] n型強磁性半導体(In,Fe)Asの価電子帯電子構造 (2018)
  • Author(s): 小林正起, Le Duc Anh, Pham Nam Hai, 原田慈久, Thorsten Schmitt, 藤森淳, 田中雅明, 尾嶋正治, Vladimir N. Strocov
  • Organizer: 第31回日本放射光学会年会・放射光科学合同シンポジウム
• [Presentation] Fe-based narrow-gap ferromagnetic semiconductors: New materials for high-performance spintronic devices (2018)
  • Author(s): Le Duc Anh, Nguyen Thanh Tu, Pham Nam Hai, Masaaki Tanaka
  • Organizer: 第9回低温センター研究交流会
• [Presentation] Transport and magnetic properties of gnetic properties of n-type ferromagnetic semiconductor (In,Fe)As co-doped with Mn: (In,Fe,Mn)As (2018)
  • Author(s): Taiki Hayakawa, Le Duc Anh, Kohei Okamoto, and Masaaki Tanaka
  • Organizer: 第9回低温センター研究交流会
• [Presentation] Spin dependent transport in an all-ferromagnetic p-InMnAs/n-InFeAs heterojunctions (2018)
  • Author(s): Kohei Okamoto, Le Duc Anh, and Masaaki Tanaka
  • Organizer: 第9回低温センター研究交流会
• [Presentation] 放射光分光による鉄系強磁性半導体の強磁性発現機構解明 (2018)
  • Author(s): 小林正起、L. D. Anh、P. N. Hai、木内久雄、宮脇淳、原田慈久、T. Schmitt、藤森淳、V. N. Strocov、尾嶋正治、田中雅明
  • Organizer: 「スピントロニクス学術研究基盤と連携ネットワーク」シンポジウム
• [Presentation] 強磁性半導体(In,Fe)As中に誘起したスピン三重項超伝導 (2018)
  • Author(s): 中村壮智、Le Duc Anh、橋本義昭、大矢忍、田中雅明、勝本信吾
  • Organizer: 「スピントロニクス学術研究基盤と連携ネットワーク」シンポジウム
• [Presentation] XMCDによるFeドープ強磁性半導体の磁化過程の研究 (2018)
  • Author(s): 坂本祥哉、Le Duc Anh、Nguyen Thanh Tu、Pham Nam Hai、竹田幸治、小林正起、中根了昌、芝田悟朗、若林勇希、高橋文雄、野中洋亮、池田啓祐、池震棟、万宇軒、鈴木雅弘、斎藤祐児、山上浩志、小出常晴、田中雅明、藤森淳
  • Organizer: 「スピントロニクス学術研究基盤と連携ネットワーク」シンポジウム
• [Presentation] Spin-dependent thermoelectric effects in (In,Fe)Sb ferromagnetic semiconductor (2018)
  • Author(s): Bui Cong Tinh, Christina Garcia, Nguyen Thanh Tu, Masaaki Tanaka, Pham Nam Hai
  • Organizer: 「スピントロニクス学術研究基盤と連携ネットワーク」シンポジウム
• [Presentation] 放射光分光による鉄系強磁性半導体の強磁性発現機構解明 (2018)
  • Author(s): 小林正起, L. D. Anh, P. N. Hai, 木内久雄, 丹羽秀治, 宮脇淳, 原田慈久, T. Schmitt, 藤森淳, V. N. Strocov, 尾嶋正治, 田中雅明
  • Organizer: ISSP-Workshop: SPring-8 BL07LSUの現状と次世代軟X線科学創成への戦略
• [Presentation] Epitaxial growth and magnetic properties of Fe delta-doped InAs thin films (2018)
  • Author(s): Le Duc Anh, Taiki Hayakawa, and Masaaki Tanaka
  • Organizer: 65th Spring Meeting of the Japan Society of Applied Physics
• [Presentation] Electrical control of ferromagnetism in the n-type ferromagnetic semiconductor (In,Fe)Sb with high Curie temperature (2018)
  • Author(s): Nguyen Thanh Tu, Pham Nam Hai, Le Duc Anh, and Masaaki Tanaka
  • Organizer: 65th Spring Meeting of the Japan Society of Applied Physics
• [Presentation] Epitaxial strain effect on ferromagnetic resonance and magnetic anisotropy of (Ga0.8,Fe0.2)Sb thin films at room temperature (2018)
  • Author(s): Shobhit Goel, Le Duc Anh, Shinobu Ohya, and Masaaki Tanaka
  • Organizer: 65th Spring Meeting of the Japan Society of Applied Physics
• [Presentation] Magnetotransport in a ferromagnetic (In,Fe)As/(In,Mn)As pn junction (2018)
  • Author(s): Kohei Okamoto, Le Duc Anh, and Masaaki Tanaka
  • Organizer: 65th Spring Meeting of the Japan Society of Applied Physics
• [Presentation] Large anisotropic magnetoresistance induced by a proximity effect in an InAs / (Ga,Fe)Sb quantum well heterostructure (2018)
  • Author(s): K. Takiguchi, L. D. Anh, K. Okamoto, T. Takeda, T. Koyama, D. Chiba, and M. Tanaka
  • Organizer: 65th Spring Meeting of the Japan Society of Applied Physics
• [Presentation] Effect of Be Doping on the Electronic Structure of n-Type Ferromagnetic Semiconductor (In,Fe)As (2018)
  • Author(s): Masaki Kobayashi, Hisao Kiuchi, Hideharu Niwa, Jun Miyawaki, Atsushi Fujimori, Le Duc Anh, Pham Nam Hai, Masaaki Tanaka, Masaharu Oshima, Yoshihisa Harada
  • Organizer: 65th Spring Meeting of the Japan Society of Applied Physics
• [Presentation] Magnetization process of the insulating ferromagnetic semiconductor (Al,Fe)Sb (2018)
  • Author(s): Shoya Sakamoto, Le Duc Anh, Pham Nam Hai, Yukiharu Takeda, Masaki Kobayashi, Ryosho Nakane, Yuki K. Wakabayashi, Yosuke Nonaka, Keisuke Ikeda1, Zhendong Chi, Yuxuan Wan, Masahiro Suzuki, Yuji Saitoh, Hiroshi Yamagami, Masaaki Tanaka, Atsushi Fujimori
  • Organizer: 65th Spring Meeting of the Japan Society of Applied Physics
• [Presentation] Magneto-thermopower in Ferromagnetic Semiconductor In1-xFexSb (2018)
  • Author(s): Cong Tinh Bui, Christina Garcia, Nguyen Thanh Tu, Masaaki Tanaka, Pham Nam Hai
  • Organizer: 65th Spring Meeting of the Japan Society of Applied Physics
• [Presentation] Tuning of Magnetoconductance by Electrical Control of Band Alignment in n+-(In,Fe)As/p+-InAs Esaki Diodes (2017)
  • Author(s): Le Duc Anh, Pham Nam Hai, and Masaaki Tanaka
  • Organizer: 9th International School and Conference on Spintronics and Quantum Information Technology (Spintech IX)
  • Int'l Joint Research
• [Presentation] High-temperature ferromagnetism in n-type and p-type Fe-doped ferromagnetic semiconductors (2017)
  • Author(s): Nguyen Thanh Tu, Pham Nam Hai, Le Duc Anh, and Masaaki Tanaka
  • Organizer: 9th International School and Conference on Spintronics and Quantum Information Technology (Spintech IX)
  • Int'l Joint Research
• [Presentation] Fe-based narrow-gap ferromagnetic semiconductor: New materials for high-performance spintronic devices (2017)
  • Author(s): Le Duc Anh, Nguyen Thanh Tu, Pham Nam Hai, and Masaaki Tanaka
  • Organizer: Collaborative Conference on Materials Research (CCMR) 2017
  • Int'l Joint Research / Invited
• [Presentation] Fe-doped ferromagnetic semiconductors for high-performance semiconductor spin devices (2017)
  • Author(s): Pham Nam Hai, Tomohiro Ostuka, Munehiko Yoshida, Nguyen Thanh Tu, Le Duc Anh, and Masaaki Tanaka
  • Organizer: 29th International Conference on Defects in Semiconductors (ICDS 2017)
  • Int'l Joint Research / Invited
• [Presentation] Control of Ferromagnetism and Transport by Material Growth and Wavefunction Engineering in Ferromagnetic Semiconductors and Heterostructures (2017)
  • Author(s): Masaaki Tanaka
  • Organizer: Spintronics X, Symposium: OP17N SPIE Nanoscience + Engineering
  • Int'l Joint Research / Invited
• [Presentation] Proximity-Induced Superconductivity in a Ferromagnetic Semiconductor (In,Fe)As (2017)
  • Author(s): Taketomo Nakamura, Le Duc Anh, Yoshiaki Hashimoto1, Yu Iwasaki, Shinobu Ohya, Masaaki Tanaka, and Shingo Katsumoto
  • Organizer: 28th International Conference on Low Temperature Physics
  • Int'l Joint Research
• [Presentation] Recent progress and topics in semiconductor spintronics and ferromagnetic semiconductors (2017)
  • Author(s): Masaaki Tanaka
  • Organizer: Junjiro Kanamori Memorial International Symposium - New Horizon of Magnetism-
  • Int'l Joint Research / Invited
• [Presentation] Transport and magnetic properties of n-type ferromagnetic semiconductor (In,Fe)As co-doped with Mn: (In,Fe, Mn)As (2017)
  • Author(s): Taiki Hayakawa, Le Duc Anh, Kohei Okamoto, and Masaaki Tanaka
  • Organizer: Junjiro Kanamori Memorial International Symposium - New Horizon of Magnetism-
  • Int'l Joint Research
• [Presentation] Valence-Band Electronic Structure of n-type Ferromagnetic Semiconductor (In,Fe)As (2017)
  • Author(s): M. Kobayashi, L. D. Anh, P. N. Hai, Y. Harada, T. Schmitt, A. Fujimori, M. Tanaka, M. Oshima, and V. N. Strocov
  • Organizer: Junjiro Kanamori Memorial International Symposium - New Horizon of Magnetism-
  • Int'l Joint Research
• [Presentation] Recent progress and topics in semiconductor spintronics and ferromagnetic semiconductors (2017)
  • Author(s): Masaaki Tanaka
  • Organizer: 5th International Meeting on Frontiers of Physics (IMFP2017)
  • Int'l Joint Research / Invited
• [Presentation] Realization of spontaneous spin splitting in the conduction band of n-type ferromagnetic semiconductor (In,Fe)As for spin-dependent band engineering (2017)
  • Author(s): Le Duc Anh, Pham Nam Hai, and Masaaki Tanaka
  • Organizer: 4th International Symposium on Advanced Magnetic Materials and Applications (ISAMMA)
  • Int'l Joint Research
• [Presentation] Valence-Band Electronic Structure of n-type Ferromagnetic Semiconductor (In,Fe)As (2017)
  • Author(s): Masaki Kobayashi, Le Duc Ahn, Pham Nam Hai, Yoshihisa Harada, Thorsten Schmitt, Atsushi Fujimori, Masaaki Tanaka, Masaharu Oshima, Vladimir N. Strocov
  • Organizer: 2017 Fall Meeting of the Japan Society of Applied Physics
• [Presentation] Transport and magnetic properties of n-type ferromagnetic semiconductor (In,Fe)As co-doped with Mn: (In,Fe, Mn)As (2017)
  • Author(s): Taiki Hayakawa, Le Duc Anh, Kohei Okamoto, and Masaaki Tanaka
  • Organizer: 2017 Fall Meeting of the Japan Society of Applied Physics
• [Presentation] n型強磁性半導体(In,Fe)As:Beの価電子帯電子構造 (2017)
  • Author(s): 小林正起, Le Duc Anh, Pham Nam Hai, 原田慈久, T. Schmitt, 藤森淳, 田中雅明, 尾嶋正治, V. N. Strocov
  • Organizer: 2017年日本物理学会秋季大会
• [Presentation] n型強磁性半導体(In,Fe)Asの電子構造に対するBe添加効果 (2017)
  • Author(s): 小林 正起, 木内 久雄, 丹羽 秀治, 宮脇 淳, 藤森 淳, Le Duc Anh, Pham Nam Hai, 田中 雅明, 尾嶋正治, 原田慈久
  • Organizer: 2017年日本物理学会秋季大会
• [Presentation] 狭ギャップ強磁性半導体とヘテロ構造の作製と機能物性 (2017)
  • Author(s): レデゥックアイン、グエンタントゥ、ファムナムハイ、田中雅明
  • Organizer: 第1回CSRN-Tokyo Workshop 2017「新しいスピントロニクス機能材料の開発とその物性制御」
  • Invited
• [Presentation] InAs/(Ga,Fe)Sb量子井戸ヘテロ接合における近接効果による大きな異方性磁気抵抗 (2017)
  • Author(s): 瀧口耕介、レデゥックアイン、岡本浩平、武田崇仁、田中雅明
  • Organizer: 第22回半導体スピン工学の基礎と応用(PASPS-22)
• [Presentation] n型強磁性半導体(In,Fe)As に Mn を共添加した強磁性半導体 (In,Fe,Mn)As の伝導および磁性 (2017)
  • Author(s): 早川奈伊紀、レデゥックアイン、岡本浩平、田中雅明
  • Organizer: 第22回半導体スピン工学の基礎と応用(PASPS-22)
• [Remarks] 田中・大矢・中根研究室
  • URL: http://www.cryst.t.u-tokyo.ac.jp/
• [Remarks] スピントロニクス学術連携研究教育センター
  • URL: http://www.csrn.t.u-tokyo.ac.jp/
• [Patent(Industrial Property Rights)] スーパー高感度異常ホール効果磁気センサー (2017)
  • Inventor(s): ファムナムハイ、田中雅明、グエンタントゥ
  • Industrial Property Rights Holder: ファムナムハイ、田中雅明、グエンタントゥ
  • Industrial Property Rights Type: 特許
  • Industrial Property Number: 特願2017-109044