Directional Spin-wave Propagation in the Skyrmion Chain

TL;DR

This paper demonstrates that skyrmion chains can serve as directional channels for spin wave propagation, with potential applications in skyrmion-based spin wave devices, using micromagnetic simulations to explore frequency-dependent behaviors.

Contribution

It reveals how skyrmion arrangements influence spin wave directionality and introduces a new approach for designing skyrmion-based spin wave channels.

Findings

Large skyrmion spacing allows frequency-based spin wave separation.

Tightly packed skyrmions enable directional spin wave propagation.

Skyrmion breathing mode frequency is key for channeling spin waves.

Abstract

The Dzyaloshinskii-Moriya interaction (DMI), favoring a chiral spin structure like the skyrmion, gives rise to the nonreciprocal propagation of spin waves. We investigate the propagation of spin waves in a nanostripe with the presence of a skyrmion chain by using micromagnetic simulations. Through applying a microwave locally, it is found that when the interval between skyrmions is large enough, the spin waves can be separated to the counter direction according to different frequencies. While for the tightly arranged skyrmions, the skyrmion chain with strong interactions between skyrmions becomes a channel for spin waves, which is around the frequency of skyrmion breathing and exhibit a characteristic of directional propagation. This work opens a vista for skyrmion-based spin wave devices.