Spin wave power flow and caustics in ultrathin ferromagnets with the Dzyaloshinskii-Moriya interaction

TL;DR

This paper theoretically investigates how the Dzyaloshinskii-Moriya interaction affects spin wave power flow in ultrathin ferromagnets, revealing unidirectional caustic beams and interface patterns due to nonreciprocal propagation.

Contribution

It introduces a theoretical analysis of spin wave power flow influenced by Dzyaloshinskii-Moriya interaction, highlighting unidirectional caustics and interface pattern formation.

Findings

Unidirectional caustic beams due to nonreciprocal spin wave propagation

Self-generated interface patterns from point-source excitation

Interaction of dipole-dipole and Dzyaloshinskii-Moriya effects influences power flow

Abstract

The Dzyaloshinskii-Moriya interaction in ultrathin ferromagnets can result in nonreciprocal propagation of spin waves. We examine theoretically how spin wave power flow is influenced by this interaction. We show that the combination of the dipole-dipole and Dzyaloshinskii-Moriya interactions can result in unidirectional caustic beams in the Damon-Eshbach geometry. Morever, self-generated interface patterns can also be induced from a point-source excitation.