Demonstration of spin-torque oscillation at near THz wave frequency

• Project/Area Number: 16K14244
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Electron device/Electronic equipment
• Research Institution: Tohoku University
• Principal Investigator: Mizukami Shigemi 東北大学, 材料科学高等研究所, 教授 (00339269)
• Co-Investigator(Kenkyū-buntansha): 鈴木 和也 東北大学, 材料科学高等研究所, 助教 (20734297)
• Co-Investigator(Renkei-kenkyūsha): KUBOTA hitoshi 産業技術総合研究所, スピントロニクス研究センター, 総括研究主幹 (30261605)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2016: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: スピントロニクス / テラヘルツ波 / スピントルクダイオード / スピンルク発振素子 / マンガン合金 / スピン注入発振 / テラヘルツ / 磁気トンネル接合

Outline of Final Research Achievements

Spin-torque oscillation is one of the auto-oscillation phenomena in spintronics which is observed in nano-scale magnetoresistive devices biased by electric current. The aim of this study is to demonstrate the spin-torque oscillation at near THz wave frequency, 0.1 THz, using our unique Mn-based alloys exhibiting spin precession at THz frequency and small damping as well as unique ultra-thin film growth techniques.
We observed, for the first time, the spin-torque-diode effect originating from the spin-torque working at the frequency over 70 GHz, near the THz wave range. In addition we obtained an insight into giant magnetoresisitive devices and its nano-fabrication for realizing the spin-torque oscillator based on Mn-based alloys for future sub-THz oscillators.

Research Products

• [Journal Article] Tunnel magnetoresistance in ultrathin L10 MnGa/MgO perpendicular magnetic tunnel junctions (2018)
  • Author(s): Suzuki K Z、Miura Y、Ranjbar R、Sugihara A、Mizukami S
  • Journal Title: Journal of Physics D: Applied Physics Volume: 51 Issue: 23 Pages: 235001-235001
  • DOI: 10.1088/1361-6463/aac00d
  • Peer Reviewed
• [Journal Article] Perpendicular magnetic tunnel junctions with Mn-modified ultrathin MnGa layer (2018)
  • Author(s): Suzuki K. Z.、Miura Y.、Ranjbar R.、Bainsla L.、Ono A.、Sasaki Y.、Mizukami S.
  • Journal Title: Applied Physics Letters Volume: 112 Issue: 6 Pages: 062402-062402
  • DOI: 10.1063/1.5002616
  • Peer Reviewed
• [Journal Article] Current-induced switching in CoGa/ L_10 MnGa/(CoGa)/Pt structure with different thicknesses (2018)
  • Author(s): Ranjbar R.、Suzuki K.Z.、Mizukami S.
  • Journal Title: Journal of Magnetism and Magnetic Materials Volume: 456 Pages: 22-30
  • DOI: 10.1016/j.jmmm.2018.02.007
  • Peer Reviewed
• [Journal Article] Ultrathin films of polycrystalline MnGa alloy with perpendicular magnetic anisotropy (2017)
  • Author(s): Atsuo Ono, Kazuya Z. Suzuki, Atsushi Sugihara, and Shigemi Mizukami
  • Journal Title: Applied Physics Express Volume: 10 Issue: 2 Pages: 023005-023005
  • DOI: 10.7567/apex.10.023005
  • NAID: 210000135758
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Thickness Dependence of Structure and Magnetic Properties of Cubic and Tetragonal Huesler Alloy Bilayer Films (2017)
  • Author(s): R. Ranjbar, K. Z. Suzuki, A. Sugihara, Y. Ando, T. Miyazaki, and S. Mizukami
  • Journal Title: Journal of Magnetism and Magnetic Materials Volume: 433 Pages: 195-201
  • DOI: 10.1016/j.jmmm.2017.03.018
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Nano-layered structure based on TM-Ga (TM = Mn,Co) alloys (2018)
  • Author(s): Shigemi Mizukami
  • Organizer: Tohoku-Purdue Workshop on Novel Spintronics Physics and Materials for Future Infomation Processing
  • Int'l Joint Research / Invited
• [Presentation] 高垂直磁気異方性と低ダンピング定数を示すマンガン合金ナノ薄膜 (2018)
  • Author(s): 水上成美
  • Organizer: 科学研究費・基盤研究 (S) 成果報告会; 規則合金スピントロニクス材料の新展開
  • Invited
• [Presentation] 極薄MnGa電極を用いた垂直磁気トンネル接合のMnGa膜厚依存性 (2017)
  • Author(s): 鈴木 和也、Reza Ranjbar、杉原 敦、水上 成美
  • Organizer: 第64回応用物理学会春季学術講演会
  • Place of Presentation: パシフィコ横浜
  • Year and Date: 2017-03-14
• [Presentation] MnGa polycrystalline ultrathin films with perpendicular magnetic anisotropy prepared on thermally-oxidized Si substrate (2017)
  • Author(s): 小野 敦央、鈴木 和也、Ranjbar Reza、水上 成美
  • Organizer: 第64回応用物理学会春季学術講演会
  • Place of Presentation: パシフィコ横浜
  • Year and Date: 2017-03-14
• [Presentation] Recent research progress on MnGa alloy nano-layer for spintronics (2017)
  • Author(s): Shigemi Mizukami and Kazuya Suzuki
  • Organizer: 15th RIEC International Workshop on Spintronics
  • Int'l Joint Research / Invited
• [Presentation] Observation of Over 70 GHz of Spin Torque Diode Effect Using MnGa/Fe Based Spin Torque Oscillator (2017)
  • Author(s): K. Mizunuma, S. Tsunegi, M. Yoshimura, M. Sato, K. Suzuki, Y. Kono, H. Wado, S. Tamaru, H. Kubota, A. Fukushima, and S. Mizukami
  • Organizer: 62nd Annual Conference on Magnetism and Magnetic Materials (MMM)
  • Int'l Joint Research
• [Presentation] Manganese-based Spintronics (Plenary) (2017)
  • Author(s): Shigemi Mizukami
  • Organizer: International Conference of Frontiers in Materials Science (FMS2017)
  • Int'l Joint Research / Invited
• [Presentation] NANO-LAYER OF TETRAGONAL Mn-BASED ALLOYS FOR MRAM APPLICATIONS (2017)
  • Author(s): Shigemi Mizukami and Kazuya Suzuki
  • Organizer: IEEE the 28th Magnetic Recording Conference (TMRC2017)
  • Int'l Joint Research / Invited
• [Presentation] Sub-THz magnetization precession and damping for manganese alloy ultrathin films (2016)
  • Author(s): Shigemi Mizukami
  • Organizer: 4th JSPS Core-to-Core Workshop on “New-Concept Spintronics Devices”
  • Place of Presentation: Tohoku Univ
  • Int'l Joint Research / Invited
• [Presentation] Mn系垂直磁化薄膜－スピントロニクスデバイスへの応用と課題 (2016)
  • Author(s): 水上成美、鈴木和也
  • Organizer: 第208回研究会/第56回化合物新磁性材料専門研究会「スピントロニクスにおける次世代材料開発」
  • Place of Presentation: 中央大学，東京
  • Invited
• [Remarks] 水上研究室ホームページ
  • URL: https://www.wpi-aimr.tohoku.ac.jp//mizukami_lab/
• [Remarks] Mizukami Lab.
  • URL: http://www.wpi-aimr.tohoku.ac.jp/mizukami_lab/