中国物理B ›› 2014, Vol. 23 ›› Issue (11): 117502-117502.doi: 10.1088/1674-1056/23/11/117502

所属专题: TOPICAL REVIEW — Magnetism, magnetic materials, and interdisciplinary research

• SPECIAL TOPIC --- Non-equilibrium phenomena in soft matters • 上一篇    下一篇

Dynamics of magnetization in ferromagnet with spin-transfer torque

李再东a, 贺鹏斌b, 刘伍明c   

  1. a Department of Applied Physics, Hebei University of Technology, Tianjin 300401, China;
    b College of Physics and Microelectronics Science, Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, Hunan University, Changsha 410082, China;
    c Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2014-07-26 修回日期:2014-09-24 出版日期:2014-11-15 发布日期:2014-11-15
  • 基金资助:

    Project supported by the Natural Science Foundation of Hebei Province of China (Grant No. A2012202022). P. B. He was supported by the Aid Program for Young Teachers of Hunan University, the Project-sponsored by SRF for ROCS, SEM, and the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institution of Hunan Province, China. W. M. Liu was supported by the National Basic Research Program of China (Grant Nos. 2011CB921502 and 2012CB821305) and the National Natural Science Foundation of China (Grant Nos. 61227902 and 61378017).

Dynamics of magnetization in ferromagnet with spin-transfer torque

Li Zai-Dong (李再东)a, He Peng-Bin (贺鹏斌)b, Liu Wu-Ming (刘伍明)c   

  1. a Department of Applied Physics, Hebei University of Technology, Tianjin 300401, China;
    b College of Physics and Microelectronics Science, Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, Hunan University, Changsha 410082, China;
    c Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2014-07-26 Revised:2014-09-24 Online:2014-11-15 Published:2014-11-15
  • Contact: Li Zai-Dong E-mail:lizd2018@live.com
  • Supported by:

    Project supported by the Natural Science Foundation of Hebei Province of China (Grant No. A2012202022). P. B. He was supported by the Aid Program for Young Teachers of Hunan University, the Project-sponsored by SRF for ROCS, SEM, and the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institution of Hunan Province, China. W. M. Liu was supported by the National Basic Research Program of China (Grant Nos. 2011CB921502 and 2012CB821305) and the National Natural Science Foundation of China (Grant Nos. 61227902 and 61378017).

摘要:

We review our recent works on dynamics of magnetization in ferromagnet with spin-transfer torque. Driven by constant spin-polarized current, the spin-transfer torque counteracts both the precession driven by the effective field and the Gilbert damping term different from the common understanding. When the spin current exceeds the critical value, the conjunctive action of Gilbert damping and spin-transfer torque leads naturally the novel screw-pitch effect characterized by the temporal oscillation of domain wall velocity and width. Driven by space- and time-dependent spin-polarized current and magnetic field, we expatiate the formation of domain wall velocity in ferromagnetic nanowire. We discuss the properties of dynamic magnetic soliton in uniaxial anisotropic ferromagnetic nanowire driven by spin-transfer torque, and analyze the modulation instability and dark soliton on the spin wave background, which shows the characteristic breather behavior of the soliton as it propagates along the ferromagnetic nanowire. With stronger breather character, we get the novel magnetic rogue wave and clarify its formation mechanism. The generation of magnetic rogue wave mainly arises from the accumulation of energy and magnons toward to its central part. We also observe that the spin-polarized current can control the exchange rate of magnons between the envelope soliton and the background, and the critical current condition is obtained analytically. At last, we have theoretically investigated the current-excited and frequency-adjusted ferromagnetic resonance in magnetic trilayers. A particular case of the perpendicular analyzer reveals that the ferromagnetic resonance curves, including the resonant location and the resonant linewidth, can be adjusted by changing the pinned magnetization direction and the direct current. Under the control of the current and external magnetic field, several magnetic states, such as quasi-parallel and quasi-antiparallel stable states, out-of-plane precession, and bistable states can be realized. The precession frequency can be expressed as a function of the current and external magnetic field.

关键词: spin-transfer torque, domain wall, soliton, ferromagnetic resonance

Abstract:

We review our recent works on dynamics of magnetization in ferromagnet with spin-transfer torque. Driven by constant spin-polarized current, the spin-transfer torque counteracts both the precession driven by the effective field and the Gilbert damping term different from the common understanding. When the spin current exceeds the critical value, the conjunctive action of Gilbert damping and spin-transfer torque leads naturally the novel screw-pitch effect characterized by the temporal oscillation of domain wall velocity and width. Driven by space- and time-dependent spin-polarized current and magnetic field, we expatiate the formation of domain wall velocity in ferromagnetic nanowire. We discuss the properties of dynamic magnetic soliton in uniaxial anisotropic ferromagnetic nanowire driven by spin-transfer torque, and analyze the modulation instability and dark soliton on the spin wave background, which shows the characteristic breather behavior of the soliton as it propagates along the ferromagnetic nanowire. With stronger breather character, we get the novel magnetic rogue wave and clarify its formation mechanism. The generation of magnetic rogue wave mainly arises from the accumulation of energy and magnons toward to its central part. We also observe that the spin-polarized current can control the exchange rate of magnons between the envelope soliton and the background, and the critical current condition is obtained analytically. At last, we have theoretically investigated the current-excited and frequency-adjusted ferromagnetic resonance in magnetic trilayers. A particular case of the perpendicular analyzer reveals that the ferromagnetic resonance curves, including the resonant location and the resonant linewidth, can be adjusted by changing the pinned magnetization direction and the direct current. Under the control of the current and external magnetic field, several magnetic states, such as quasi-parallel and quasi-antiparallel stable states, out-of-plane precession, and bistable states can be realized. The precession frequency can be expressed as a function of the current and external magnetic field.

Key words: spin-transfer torque, domain wall, soliton, ferromagnetic resonance

中图分类号:  (Domain walls and domain structure)

  • 75.60.Ch
72.25.Ba (Spin polarized transport in metals) 75.78.-n (Magnetization dynamics) 75.40.Gb (Dynamic properties?)