Theory of the spin-torque-driven ferromagnetic resonance in a ferromagnetormal-metal/ferromagnet structure

摘要

We present a theoretical analysis of current-driven ferromagnetic resonance in a ferromagnetormal-metal/ ferromagnet trilayer. This method of driving ferromagnetic resonance was recently realized experimentally by Tulapurkar et al. [Nature 438, 339 (2005)] and Sankey et al [Phys. Rev. Lett. 96, 227601 (2006)]. The precessing magnetization rectifies the alternating current applied to drive the ferromagnetic resonance and leads to the generation of a dc voltage. Our analysis shows that a second mechanism to generate a dc voltage, rectification of spin currents emitted by the precessing magnetization, has a contribution to the dc voltage that is of approximately equal size for the thin ferromagnetic films used in the experiment.