Micromagnetic Modeling of Surface Acoustic Wave Driven Dynamics: Interplay of Strain, Magnetorotation, and Magnetic Anisotropy

TL;DR

This paper investigates how surface acoustic waves interact with spin waves in a thin magnetic film, revealing how anisotropy orientation can tune their coupling for magnonic applications.

Contribution

It provides a comprehensive micromagnetic model including strain and lattice rotation effects, highlighting the role of anisotropy in SAW-SW coupling.

Findings

SAW magnetoacoustic excitation field fully implemented

Anisotropy orientation tunes the parallel resonant interaction

Provides a unified picture of SAW-SW coupling in thin films

Abstract

We study the coupling mechanism of surface acoustic waves (SAW) with spin waves (SW) using micromagnetic analysis. The SAW magnetoacoustic excitation field is fully implemented, i.e., all strain and lattice-rotation terms are included. A realistic CoFeB film with a weak in-plane uniaxial anisotropy is considered. We investigate the conditions for efficient SAW--SW coupling, with particular emphasis on the case where the SAW propagates parallel to the external magnetic field, a configuration of special interest for magnonic applications. Remarkably, we find that the anisotropy orientation serves as a knob to tune the parallel resonant interaction. Overall, this work provides a unified and practical picture of SAW--SW coupling in thin magnetized films.