Spin excitations in the skymion host Cu2OSeO3

TL;DR

This study uses inelastic neutron scattering to explore magnetic excitations in Cu2OSeO3, revealing mostly consistent results with existing models but also highlighting the importance of anisotropic interactions for understanding skyrmion states.

Contribution

It provides experimental data on magnetic excitations in Cu2OSeO3 and identifies the need to include anisotropic interactions in theoretical models.

Findings

Most data align with existing magnetic excitation models.

Identification of two energy scales indicating anisotropic interactions.

Suggests future models should incorporate anisotropy for accuracy.

Abstract

We have used inelastic neutron scattering to measure the magnetic excitation spectrum along the high-symmetry directions of the first Brillouin zone of the magnetic skyrmion hosting compound Cu$_2$OSeO$_3$. The majority of our scattering data are consistent with the expectations of a recently proposed model for the magnetic excitations in Cu$_2$OSeO$_3$, and we report best-fit parameters for the dominant exchange interactions. Important differences exist, however, between our experimental findings and the model expectations. These include the identification of two energy scales that likely arise due to neglected anisotropic interactions. This feature of our work suggests that anisotropy should be considered in future theoretical work aimed at the full microscopic understanding of the emergence of the skyrmion state in this material.