Enhancement of sensitivity in high-frequency radio-wave magnetic detectors by using current-induced torque acting as magnetic field

• Project/Area Number: 25790045
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Applied materials
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: MATSUMOTO Rie 独立行政法人産業技術総合研究所, スピントロニクス研究センター, 研究員 (10635303)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2013: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
• Keywords: スピントロニクス / スピントルク / ダイオード / 磁気共鳴

Outline of Final Research Achievements

We proposed a method to enhance spin-torque diode (STD) sensitivity by using an antiphase dynamic coupling (ADC) of the free and reference layers. The ADC was found in STD measurements of MgO-based magnetic tunnel junctions and also in micromagnetic simulations. In order to investigate the optimal conditions for the ADC, we developed an analytical expression for the STD effect caused by the magnetization dynamics in the reference layers. From the analytical expressions, we found that inducing interaction between the reference and magnetic-pinned layers through the spin torque is more advantageous to the ADC than inducing interaction between the reference and free layers. The analytical expression also made it possible to evaluate quantitatively the spin-torque interactions working on the reference layer.

Research Products

• [Journal Article] Spin-torque diode spectrum of a spin valve with a synthetic antiferromagnetic reference layer (2014)
  • Author(s): Matsumoto, Hitoshi Kubota, Toshiki Yamaji, Hiroko Arai, Shinji Yuasa and Hiroshi Imamura
  • Journal Title: Japanese Journal of Applied Physics Volume: 53 Issue: 12 Pages: 123001-123001
  • DOI: 10.7567/jjap.53.123001
  • NAID: 210000144662
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Effect of spin-transfer-torque induced dynamics of a synthetic antiferromagnetic reference layer on a spin-torque diode spectrum (2015)
  • Author(s): Rie Matsumoto*, Hitoshi Kubota, Toshiki Yamaji, Hiroko Arai, Shinji Yuasa, and Hiroshi Imamura
  • Organizer: 20th International Conference on Magnetism (ICM2015)
  • Place of Presentation: Spain, Barcelona
  • Year and Date: 2015-07-05 – 2015-07-10
• [Presentation] Enhancement of spin-torque diode sensitivity at high-frequency by utilizing anti-phase dynamic coupling of free and reference layers (2014)
  • Author(s): R. Matsumoto, H. Kubota, T. Yamaji, H. Arai, H. Imamura, K. Yakushiji, A. Fukushima, S. Yuasa
  • Organizer: The 59th Annual Magnetism and Magnetic Materials (MMM) Conference
  • Place of Presentation: Honolulu, U.S.A.
  • Year and Date: 2014-11-05
• [Presentation] Enhancement of spin-torque diode sensitivity at high-frequency by utilizing dynamic coupling of free and reference layers (2014)
  • Author(s): R. Matsumoto, H. Kubota, T. Yamaji, H. Arai, H. Imamura, K. Yakushiji, A. Fukushima, S. Yuasa
  • Organizer: 第75回応用物理学秋季学術講演会
  • Place of Presentation: 北海道大学 札幌キャンパス
  • Year and Date: 2014-09-05
• [Presentation] Bias Voltage Dependence of Field-like Torque in Asymmetric CoFeB/MgO/CoFe/NiFe Magnetic Tunnel Junctions (2013)
  • Author(s): R. Matsumoto, H. Kubota, H. Imamura, S. Tamaru, K. Yakushiji, A. Fukushima, S. Yuasa
  • Organizer: 第74回応用物理学会秋季学術講演会
  • Place of Presentation: 同志社大学 京田辺キャンパス