Two-magnon scattering in the framework of the Lippmann-Schwinger equation

Abstract

Controlling magnetic losses requires identifying the microscopic origin of extrinsic linewidth broadening. We introduce a Lippmann--Schwinger framework for two-magnon scattering from weak defect potentials, showing that scattering is set by the overlap between the perturbation of the effective field and degenerate spin-wave states. Applied to iron garnet films, YIG/GGG(111) and YIG/GGG(110), we identify crystallographic directions along which these perturbation are elongated. This approach provides a link between the crystallography, effective field on the sample scale and two-magnon scattering.