Current-driven transverse domain wall oscillations in perpendicular spin-valve structures

Article

关键词: ORBIT TORQUE;    NANO-OSCILLATOR;    PHASE-LOCKING;    MAGNETORESISTANCE;    MAGNETIZATION;    GENERATION;    EXCITATION;    EMISSION;    MOTION;   

DOI  :  10.1103/PhysRevB.102.014405

来源: SCIE

【 摘 要 】

Spin-transfer-driven oscillations of a transverse domain wall confined to a perpendicular spin-valve structure are investigated using a one-dimensional model. The stack consists of a polarizer, nonmagnetic spacer, soft free layer, and pinned magnetic layer. It is found that the domain-wall oscillation frequency is a nonmonotonic, highly asymmetrical function of applied electric current, showing a strong dependence on the current direction and the relative strengths of the interfacial and bulk spin-transfer torques. Micromagnetic analysis reveals that the surprising and atypical oscillator response is due to an interplay between the interfacial spin-transfer torque, the bulk spin-transfer torque, the exchange torque, and the damping torque. The underlying physical and material responses are examined, including the important role of the domain-wall twist. The competitions between the involved torques under different operating conditions suggest that the oscillator could serve as a model system to investigate magnetic and spintronic phenomena at the nanoscale. The observed current-dependent twisting of the free-layer magnetization about the axis of precession may further be found interesting for investigations of the interaction between spin-polarized current and chiral spin structures.

【 授权许可】

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