Ferromagnetic resonance with magnetic phase selectivity by means of resonant elastic x-ray scattering on a chiral magnet

TL;DR

This paper introduces a novel resonant elastic x-ray scattering technique to selectively probe ferromagnetic resonance modes in chiral magnets, enabling detailed analysis of skyrmion lattice dynamics.

Contribution

The study presents REXS-FMR, a new method combining resonant elastic x-ray scattering with GHz magnetic excitation to distinguish magnetic states and modes in skyrmion-hosting materials.

Findings

Detected all three eigenmodes of the skyrmion lattice with high sensitivity.

Enabled mode-specific analysis by probing different reciprocal space positions.

Provided detailed information on mode mixing and magnetic state contributions.

Abstract

Cubic chiral magnets, such as Cu$_{2}$OSeO$_{3}$, exhibit a variety of non-collinear spin textures, including a trigonal lattice of spin whirls, so-called skyrmions. Using magnetic resonant elastic x-ray scattering (REXS) on a crystalline Bragg peak and its magnetic satellites while exciting the sample with magnetic fields at GHz frequencies, we probe the ferromagnetic resonance modes of these spin textures by means of the scattered intensity. Most notably, the three eigenmodes of the skyrmion lattice are detected with large sensitivity. As this novel technique, which we label REXS-FMR, is carried out at distinct positions in reciprocal space, it allows to distinguish contributions originating from different magnetic states, providing information on the precise character, weight and mode mixing as a prerequisite of tailored excitations for applications.