Magnetoelectric nature of skyrmions in a chiral magnetic insulator Cu2OSeO3

TL;DR

This study reveals that skyrmions in the chiral magnetic insulator Cu2OSeO3 exhibit magnetoelectric coupling, with electric polarization induced by magnetic fields, enabling potential electric control of skyrmion dynamics.

Contribution

It demonstrates the magnetoelectric nature of skyrmions in Cu2OSeO3 and explains the phenomenon using the d-p hybridization model, highlighting the role of spin-orbit interaction.

Findings

Skyrmions induce electric polarization depending on magnetic field direction.

The polarization behavior is explained by the d-p hybridization model.

Skyrmions can carry local electric dipoles or quadrupoles, enabling electric control.

Abstract

Dielectric properties were investigated under various magnitudes and directions of magnetic field (H) for a chiral magnetic insulator Cu2OSeO3. We found that the skyrmion crystal induces electric polarization (P) along either in-plane or out-of-plane direction of the spin vortices depending on the applied H-direction. The observed H-dependence of P in ferrimagnetic, helimagnetic, and skyrmion crystal state can be consistently described by the d-p hybridization model, highlighting an important role of relativistic spin-orbit interaction in the magnetoelectric coupling in Cu2OSeO3. Our analysis suggests that each skyrmion particle can locally carry electric dipole or quadrupole, which implies that the dynamics of skyrmions are controllable by the external electric field.