Spin Wave Emitting Effect Caused by Current-induced Spin Transfer Torque in PSV

Abstract： This article presents a magnetic dynamics description for current-induced STT in PSV, which could illuminate that the effects of SWE and CIMS in magnetic multiplayer nanostructures. The spin current polarization is determined by the continuity boundary condition of spin current and chemical potential under the case of conduction matching. The roles of longitudinal and transverse components of STT are different in magnetic multiplayer that longitudinal one generates CIMS effect, while transverse one is necessary for SWE effect. From the theory, the double spin wave modes have been naturally obtained by LLG equation, which are x mode and y mode, respectively, due to the transverse STT, and cause resistance of magnetic multiplayer altering following time with frequency 2w or w(precession frequency). Magnetic field and spin current control frequency and power of SWE according to this theory, which predicts a special device structure, for example, the perpendicular configuration, should present much higher efficiency of SWE that has been demonstrated by some experiment results.