Interaction between surface acoustic waves and spin waves in a ferromagnetic thin film

強磁性薄膜における表面音波とスピン波の相互作用

山本 慧   ; Xu, M.*; Puebla, J.*; 大谷 義近*; 前川 禎通*

Yamamoto, Kei; Xu, M.*; Puebla, J.*; Otani, Yoshichika*; Maekawa, Sadamichi*

We present a theoretical description of magnon-phonon interactions in a multi-layer structure containing a ferromagnetic thin film. The formalism is applicable to an arbitrary direction of external magnetic field and various types of acoustic waves including Rayleigh and Love surface modes. A particular attention is paid to the spatial profile of the acoustic wave modes and analytical expressions for the effective coupling coefficients are derived taking into account the degree of mode profile overlap between spin waves and acoustic waves. The results are applied to reproduce a strongly anisotropic and non-reciprocal linewidth of acoustic ferromagnetic resonance reported in a recent experiment.