Anatomy of Spin Wave Polarization in Ferromagnets

TL;DR

This paper systematically analyzes how various magnetic interactions influence spin wave polarization in ferromagnets, providing predictive principles applicable to diverse magnetic textures.

Contribution

It introduces a comprehensive framework to predict spin wave polarization traits based on magnetic interactions and textures, advancing understanding of polarization dynamics in ferromagnetic systems.

Findings

Magnetic interactions can induce elliptical polarization in spin waves.

The framework predicts polarization degree and orientation from equilibrium textures.

Application to complex magnetic structures demonstrates broad applicability.

Abstract

Spin waves in ferromagnetic materials are predominantly characterized by right-handed circular polarization due to symmetry breaking induced by net magnetization. However, magnetic interactions, including the external magnetic field, Heisenberg exchange, Dzyaloshinskii-Moriya interaction, and dipole-dipole interaction, can modify this behavior, leading to elliptical polarization. This study provides a systematic analysis of these interactions and their influence on spin wave polarization, establishing principles to predict traits such as polarization degree and orientation based on equilibrium magnetization textures. The framework is applied to diverse magnetic configurations, including spin spirals, domain walls, and Skyrmions, offering a comprehensive yet simple approach to understanding polarization dynamics in ferromagnetic systems.