Pt/強磁性体複合構造における超スピン流物性の開拓と構造依存性

• Project/Area Number: 10J05780
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 国内
• Research Field: 物性Ⅱ(磁性・金属・低温)(実験)
• Research Institution: Tohoku University
• Principal Investigator: 梶原 瑛祐 東北大学, 大学院・理学研究科, 特別研究員(DC1)
• Project Period (FY): 2010 – 2012
• Project Status: Completed (Fiscal Year 2012)
• Budget Amount: ¥2,100,000 (Direct Cost: ¥2,100,000); Fiscal Year 2012: ¥700,000 (Direct Cost: ¥700,000); Fiscal Year 2011: ¥700,000 (Direct Cost: ¥700,000); Fiscal Year 2010: ¥700,000 (Direct Cost: ¥700,000)
• Keywords: スピン流 / 超スピン流 / スピン波スピン流 / スピンポンピング / Mott絶縁体 / スピントルク / (逆)スピンホール効果 / パラメトリック励起 / スピン波共鳴

Research Abstract

磁場を介しないスピン制御に基づいた次世代メモリや低損失な量子情報伝送技術の創出に向けて、電子スピン角運動量の流れであるスピン流物性に関する研究に大きな興味が集まっている。これまでのスピン流に関する研究のほとんどは、伝導電子が運ぶスピン流:伝導電子スピン流のみに焦点があてられ、物質系も金属合金や半導体に限られていたのが現状である。しかし、スピン流の学理を構築するためには、あらゆる物質系や電子相でも適用できる、スピン流の応答や伝搬機構に関する体系的理解が不可欠であることは明らかである。本研究は、伝導電子スピン流および金属合金・半導体に限られてきたスピン流物性の研究をより一般的な枠組みに拡張し、スピン流物性の体系を構築することにある。このような中、前年度までに研究者は研究目的の1つであった絶縁体中を流れる超スピン流(スピン波スピン流)を初めて観測した。本研究成果は、これまで伝導電子スピン流に限られてきたスピン流の概念を拡張するものである。
前年度までの成果を踏まえ本年度は、さらに様々な電子相でのスピン流物性、とくに複合膜界面でのスピン角運動量交換機構に関して理解することをめざした。申請者は、様々な界面構造を有する白金/磁性体ガーネット複合構造において、超スピン流と伝導電子スピン流とのスピン角運動量交換効率をスピンポンプ法によって評価した。その結果、スピン流交換効率が、試料構造の作製過程および界面構造に強く依存していることが明らかとなった。本研究で、界面観察電子技術を併用することにより、巨大なスピン流交換効率を実現する複合界面状態を見出した。本研究で見積もられたスピン流交換効率は、理論的に計算された値と整合した。本研究により、複合膜界面での実験と理論の両面からの、スピン流交換に関するより詳細な検討が可能となり、スピン流交換メカニズムに関する具体的な議論が可能となった。

Research Products

• [Journal Article] All-oxide system for spin pumping (2012)
  • Author(s): Z. Qiu, Y. Kajiwara, K. Ando, Y. Fujikawa, K. Uchida, T. Tashiro, K. Harii, T. Yoshino, and E. Saitoh
  • Journal Title: Applied Physics Letters Volume: 100 Issue: 2
  • DOI: 10.1063/1.3675463
  • Peer Reviewed
• [Journal Article] Scaling fit of spin pumping in various ferromagnetic materials (2012)
  • Author(s): T. Yoshino, K. Ando, Y. Kajiwara, H. Nakayama, and E. Saitoh
  • Journal Title: Journal of Applied Physics Volume: 111 Issue: 7
  • DOI: 10.1063/1.3670462
  • Peer Reviewed
• [Journal Article] Suppression of Spin Pumping in the Presence of Thin Titanium Interface (2012)
  • Author(s): H. Nakayama, T. Tashiro, R. Takahashi, Y. Kajiwara, T. Ohtani, K. Ando, R. Iguchi, K. Uchida, T. Yoshino, and E. Saitoh
  • Journal Title: Key Engineering Materials Volume: 508 Pages: 347-352
  • DOI: 10.4028/www.scientific.net/kem.508.347
  • Peer Reviewed
• [Journal Article] Spin pumping in a ferromagnetic/nonmagnetic/spin sink trilayer film : spin current termination (2012)
  • Author(s): K. Harii, Z. Qiu, T. Iwashita, Y. Kajiwara, K. Uchida, K. Ando, T. An, Y. Fujikawa, and E. Saitoh
  • Journal Title: Key Engineering Materials Volume: 508 Pages: 266-270
  • DOI: 10.4028/www.scientific.net/kem.508.266
  • Peer Reviewed
• [Journal Article] Geometry dependence on inverse spin Hall effect induced by spin pumping in Ni_<81>Fe_<19>/Pt films (2012)
  • Author(s): H. Nakayama, K. Ando, K. Harii, T. Yoshino, R. Takahashi, Y. Kajiwara, K. Uchida, Y. Fujikawa, and E. Saitoh
  • Journal Title: Physical Review B Volume: 85 Issue: 14
  • DOI: 10.1103/physrevb.85.144408
  • Peer Reviewed
• [Journal Article] Thermal spin pumping and magnon-phonon-mediated spin-Seebeck effect (2012)
  • Author(s): K. Uchida, T. Ota, H. Adachi, J. Xiao, T. Nonaka, Y. Kajiwara, G. E. W. Bauer, S. Maekawa, and E. Saitoh
  • Journal Title: Journal of Applied Physics Volume: 111 Issue: 10
  • DOI: 10.1063/1.4716012
  • Peer Reviewed
• [Journal Article] Interface induced inverse spin Hall effect in bismuth/permalloy bilayer (2012)
  • Author(s): D. Hou, Z. Qiu, K. Harii, Y. Kajiwara, K. Uchida, Y. Fujikawa, H. Nakayama, T. Yoshino, T. An, K. Ando, X. Jin, and E. Saitoh
  • Journal Title: Applied Physics Letters Volume: 101 Issue: 4 Pages: 0424031-4
  • DOI: 10.1063/1.4738786
  • Peer Reviewed
• [Journal Article] Spin-current driven thermoelectric coating (2012)
  • Author(s): A. Kirihara, K. Uchida, Y. Kajiwara, M. Ishida, Y. Nakamura, T. Manako, E. Saitoh, and S. Yorozu
  • Journal Title: Nature Materials Volume: 11 Issue: 8 Pages: 686-689
  • DOI: 10.1038/nmat3360
  • Peer Reviewed
• [Journal Article] Inverse spin-Hall effect induced by spin pumping in metallic system (2011)
  • Author(s): K.Ando, S.Takahashi, J.Ieda, Y.Kajiwara, H.Nakayama, T.Yoshino, K.Harii, Y.Fujikawa, M.Matsuo, S.Maekawa, E.Saitoh
  • Journal Title: Journal of applied physics Volume: 103 Issue: 10
  • DOI: 10.1063/1.3587173
  • Peer Reviewed
• [Journal Article] Spin pumping by parametrically excited exchange magnons (2011)
  • Author(s): C.W.Sandweg, Y.Kajiwara, A.V.Chumak, A.A.Serga, V.I.Vasyuchka, M.B.Jungfleisch, E.Saitoh, B.Hillebrands
  • Journal Title: Physical Review Letters Volume: 106 Issue: 21
  • DOI: 10.1103/physrevlett.106.216601
  • Peer Reviewed
• [Journal Article] モット絶縁体へのスピン注入 (2011)
  • Author(s): 梶原瑛祐, 齊藤英治
  • Journal Title: 固体物理 Volume: 46 Pages: 155-164
  • NAID: 40018814885
• [Journal Article] Detection of spin-wave spin current in a magnetic insulator (2011)
  • Author(s): Y.Kajiwara, S.Takahashi, S.Maekawa, E.Saitoh
  • Journal Title: IEEE Transaction on Magnetics Volume: 47 Issue: 6 Pages: 1591-1594
  • DOI: 10.1109/tmag.2011.2118747
  • Peer Reviewed
• [Journal Article] Spin current depolarization under high electric fields in undoped InGaAs (2011)
  • Author(s): N.Okamoto, H.Kurebayashi, K.Harii, Y.Kajiwara, H.Beere, I.Farrer, T.Trypiniotis, K.Ando, D.A.Ritchie, C.H.W.Barnes, E.Saitoh
  • Journal Title: Applied Physics Letters Volume: 98 Issue: 24
  • DOI: 10.1063/1.3599599
  • Peer Reviewed
• [Journal Article] Frequency Dependence of Spin Pumping in Pt/Y3Fe5O12 Film (2011)
  • Author(s): K.Harii, T.An, Y.Kajiwara, K.Ando, H.Nakayama, T.Yoshino, E.Saitoh
  • Journal Title: Journal of Applied Physics Volume: 109 Issue: 11 Pages: 1161051-3
  • DOI: 10.1063/1.3594661
  • Peer Reviewed
• [Journal Article] Electric detection of the spin-Seebeck effect in magnetic insulator in the presence of interface barrier (2011)
  • Author(s): K.Uchida, T.Ota, Y.Kajiwara, H.Umezawa, H.Kawai, E.Saitoh
  • Journal Title: Journal of Physics : Conference Series Volume: 303 Pages: 012096-012096
  • DOI: 10.1088/1742-6596/303/1/012096
  • Peer Reviewed
• [Journal Article] Spin pumping in polycrystalline magnetic insulator/metal Pt films (2011)
  • Author(s): Y.Kajiwara, K.Ando, H.Nakayama, R.Takahashi, E.Saitoh
  • Journal Title: IEEE Transaction on Magnetics Volume: 47 Issue: 10 Pages: 2739-2742
  • DOI: 10.1109/tmag.2011.2150737
  • Peer Reviewed
• [Journal Article] Inverse spin-Hall effect induced by spin pumping in different size Ni81Fe19/Pt films (2011)
  • Author(s): H.Nakayama, K.Ando, K.Harii, Y.Fujikawa, Y.Kajiwara, T.Yoshino, E.Saitoh
  • Journal Title: Journal of Physics (conference series) Volume: 266
  • Peer Reviewed
• [Journal Article] Quantifying spin mixing conductance in F/Pt (F=Ni, Fe, and Ni81Fe19) bilayer film (2011)
  • Author(s): T.Yoshino, K Ando, K Harii, H Nakayama, Y Kajiwara, E.Saitoh
  • Journal Title: Journal of Physics (conference series) Volume: 266
  • Peer Reviewed
• [Journal Article] Universality of the spin pumping in metallic bilayer films (2011)
  • Author(s): T.Yoshino, K.Ando, K.Harii, H.Nakayama, Y.Kajiwara, E.Saitoh
  • Journal Title: Applied Physics Letter Volume: 98
  • Peer Reviewed
• [Journal Article] Spin pumping in polycrystalline magnetic insulator/metal Pt films (2011)
  • Author(s): Y.Kajiwara, K.Ando, H.Nakayama, R.Takahashi, E.Saitoh
  • Journal Title: IEEE Transactions on Magnetics Volume: (印刷中 未定)
  • Peer Reviewed
• [Journal Article] Transmission of electrical signals by spin-wave interconversion in a magnetic insulator (2010)
  • Author(s): Y.Kajiwara, K.Harii, S.Takahashi, J.Ohe, K.Uchida, M.Mizuguchi, H.Umezawa, H.Kawai, K.Ando, K.Takanashi, S.Maekawa, E.Saitoh
  • Journal Title: Nature Volume: 464 Pages: 262-266
  • Peer Reviewed
• [Journal Article] Angular dependence of inverse spin-Hall effect induced by spin pumping : experimental verification of phenomenological model of spin pumping (2010)
  • Author(s): K.Ando, T.Yoshino, N.Okamoto, Y.Kajiwara, K.Sasage, K.Uchida, E.Saitoh
  • Journal Title: Journal of Magnetism and Magnetic Materials Volume: 322 Pages: 1422-1424
  • Peer Reviewed
• [Journal Article] Inverse spin-Hall effect induced by spin pumping in various metals (2010)
  • Author(s): K.Ando, Y.Kajiwara, K.Sasage, K.Uchida, E.Saitoh
  • Journal Title: IEEE transactions on magnetics Volume: 46 Pages: 1331-1333
  • Peer Reviewed
• [Journal Article] Inverse spin-Hall effect induced by spin pumping in different thickness Pt films (2010)
  • Author(s): H.Nakayama, K.Ando, K.Harii, Y.Kajiwara, T.Yoshino, K.Uchida, E.Saitoh
  • Journal Title: IEEE Transaction on Magnetics Volume: 46 Pages: 2202-2204
  • Peer Reviewed
• [Journal Article] Spin Seebeck insulator (2010)
  • Author(s): K.Uchida, J.Xiao, H.Adachi, J.Ohe, S.Takahashi, J.Ieda, T.Ota, Y.Kajiwara, H.Umezawa, H.Kawai, G.E.W.Bauer, S.Maekawa, E.Saitoh
  • Journal Title: Nature materials Volume: 9 Pages: 894-897
  • Peer Reviewed
• [Journal Article] Enhancement of the spin pumping efficiency by spin wave mode selection (2010)
  • Author(s): C.W.Sandweg, Y.Kajiwara, K.Ando, E.Saitoh, B.Hillebrands
  • Journal Title: Applied Physics Letters Volume: 97
  • Peer Reviewed
• [Journal Article] 磁性絶縁体を用いたスピン流の伝送 (2010)
  • Author(s): 梶原瑛祐, 安藤和也, 齊藤英治
  • Journal Title: まてりあ Volume: 49 Pages: 575-579
  • NAID: 10027472178
• [Presentation] 熱誘起スピントルクによるスピンポンピング誘起スピン流の制御 (2012)
  • Author(s): 梶原瑛祐, 内田健一, 齊藤英治
  • Organizer: 日本物理学会春季大会
  • Place of Presentation: 関西学院大学西宮キャンパス
  • Year and Date: 2012-03-26
• [Presentation] Enhancement of spin-pumping voltage through the spin-Seebeck effect (2011)
  • Author(s): Y.Kajiwara, E.Saitoh
  • Organizer: SpincaloritoronicsIII
  • Place of Presentation: Lorentz center, the Netherlands
  • Year and Date: 2011-05-12
• [Presentation] YIG/Pt系におけるスピン流パラメトリック励起の観測 (2011)
  • Author(s): 梶原瑛祐, Christian Sandweg, Andrii Chumak, Alexander Serga, 安藤和也, Burkard Hillebrallds, 齊藤英治
  • Organizer: 物理学会 第66回年次大会
  • Place of Presentation: 新潟大学五十嵐キャンパス
  • Year and Date: 2011-03-25
• [Presentation] Transmission of electrical signals by spin-wave interconversion in a magnetic insulator (2010)
  • Author(s): Y.Kajiwara, E.Saitoh
  • Organizer: Spin Wave Aspects in Spintronics
  • Place of Presentation: Kaiserslautern, German
  • Year and Date: 2010-10-05
• [Presentation] Spin transfer at an interface between a magnetic insulator Y3Fe5O12 and Pt (2010)
  • Author(s): Y.Kajiwara, E.Saitoh
  • Organizer: Joint European Magnetic Symposia (JEMS) 2010
  • Place of Presentation: Krakow, Poland
  • Year and Date: 2010-08-25
• [Presentation] Spin pumping and spin-transfer torque in magnetic insulator/metal interface (2010)
  • Author(s): Y.Kajiwara, E.Saitoh
  • Organizer: ISAMMA 2010
  • Place of Presentation: Sendai, Japan
  • Year and Date: 2010-07-15