Generation of Spin Currents in the Skyrmion Phase of a Helimagnetic Insulator $\mathrm{Cu_2OSeO_3}$

TL;DR

This study demonstrates that magnetic skyrmions in the helimagnetic insulator Cu2OSeO3 can generate spin currents when resonantly excited by microwaves, with detectable signals via the inverse spin Hall effect in an attached platinum layer.

Contribution

It reveals that skyrmion dynamics contribute to spin pumping effects in an insulator, expanding understanding of spin current generation mechanisms.

Findings

Spin currents are generated in Cu2OSeO3 during skyrmion resonance.

Inverse spin Hall effect signals are observed in both skyrmion and ferrimagnetic phases.

Skyrmions contribute to the spin pumping effect in insulators.

Abstract

We report spin-current generation related with skyrmion dynamics resonantly excited by a microwave in a helimagnetic insulator $\mathrm{Cu_2OSeO_3}$. A Pt layer was fabricated on $\mathrm{Cu_2OSeO_3}$ and voltage in the Pt layer was measured upon magnetic resonance of $\mathrm{Cu_2OSeO_3}$ to electrically detect injected spin currents via the inverse spin Hall effect (ISHE) in Pt. We found that ISHE-induced electromotive forces appear in the skyrmion phase of $\mathrm{Cu_2OSeO_3}$ as well as in the ferrimagnetic phase, which shows that magnetic skyrmions can contribute to the spin pumping effect.