Spin transfer torque in lateral spin-valve structure evaluated from field-excited ferromagnetic resonant linewidth

Modulation of ferromagnetic resonance (FMR) linewidth owing to a spin transfer torque (STT) caused by the absorption of a pure spin current in a permalloy nanowire is demonstrated. To exclude the STT induced by the spin-polarized current, the pure spin current was produced using a lateral spin-valve structure. Self-homodyne FMR detection without applying an external sense current was used for minimizing the influence of Joule heating on the FMR linewidth. The linear variation of the FMR linewidth caused by the STT was clearly observed when the electrical current generating the pure spin current was below 1 mA. (C) 2015 The Japan Society of Applied Physics