Micromagnetic simulations of magnetoelastic spin wave excitation in scaled magnetic waveguides

TL;DR

This study uses micromagnetic simulations to demonstrate how nonuniform magnetization in scaled magnetic waveguides enables efficient spin wave excitation via the magnetoelastic effect, especially with biaxial in-plane strains.

Contribution

It reveals that nonuniform magnetization due to demagnetizing fields enables spin wave excitation by normal strains, highlighting the effectiveness of biaxial in-plane strain in scaled waveguides.

Findings

Nonuniform magnetization enables spin wave excitation by normal strains.

Biaxial in-plane strain excites spin waves more efficiently than uniaxial out-of-plane strain.

Excitation efficiency in 200 nm wide waveguides is comparable to shear strain.

Abstract

We study the excitation of spin waves in scaled magnetic waveguides using the magnetoelastic effect. In uniformly magnetized systems, normal strains parallel or perpendicular to the magnetization direction do not lead to spin wave excitation since the magnetoelastic torque is zero. Using micromagnetic simulations, we show that the nonuniformity of the magnetization in submicron waveguides due to the effect of the demagnetizing field leads to the excitation of spin waves for oscillating normal strains both parallel and perpendicular to the magnetization. The excitation by biaxial normal in-plane strain was found to be much more efficient than by uniaxial normal out-of-plane strain. For narrow waveguides with widths of 200\,nm, the excitation efficiency of biaxial normal in-plane strain was comparable to that of shear strain.