Scattering theory of spin waves by lattice dislocation defects

TL;DR

This paper explores how lattice dislocations in magnetic insulators affect spin-wave propagation, revealing their role as tunable scattering centers that influence magnonic device performance.

Contribution

It introduces a continuum magnetoelastic model to analyze dislocation-induced magnetic textures and their impact on spin-wave scattering, combining numerical and analytical methods.

Findings

Dislocations create localized scattering potentials affecting spin waves.

Magnetoelastic coupling leads to asymmetric scattering responses.

Dislocations can modulate spin-wave transport and break reflectionless behavior.

Abstract

We investigate spin-wave propagation in magnetic insulators in the presence of lattice dislocations. Within a continuum magnetoelastic framework, we show that the strain fields generated by dislocations induce equilibrium magnetic textures. The morphology of these textures depends sensitively on the dislocation type and acts as a localized scattering potential for spin-wave excitations. As a result, the scattering response exhibits pronounced asymmetries and interference effects governed by the magnetoelastic coupling and the dislocation type. By combining numerical simulations with analytical scattering theory, we compute differential cross sections and frequency-dependent transmission coefficients. Furthermore, analysis of the effective potential landscape reveals that the defect forms a barrier that modulates spin-wave transport and, crucially, breaks the intrinsic reflectionless nature of magnetic domain walls. Our findings identify lattice dislocations as tunable scattering centers, opening new avenues for defect engineering in magnonic devices.