Acoustic-Driven Magnetic Skyrmion Motion

TL;DR

This paper demonstrates experimentally that surface acoustic waves can effectively manipulate Ne9el-type skyrmions in multilayer films, revealing directional control and potential for low-power spintronic applications.

Contribution

It provides the first experimental evidence of skyrmion motion driven by propagating acoustic waves, including directional control via Rayleigh and shear horizontal waves.

Findings

Shear horizontal waves effectively drive skyrmion motion.

Rayleigh waves trap skyrmions without inducing motion.

Micromagnetic simulations confirm experimental observations.

Abstract

Magnetic skyrmions have great potential for developing novel spintronic devices. The electrical manipulation of skyrmions has mainly relied on current-induced spin-orbit torques. A recent theoretical model suggested that the skyrmions could be more efficiently manipulated by surface acoustic waves (SAW), an elastic wave that can couple with magnetic moment through magnetoelastic effect. However, the directional motion of skyrmions that is driven by SAW is still missing. Here, we experimentally demonstrate the motion of N\'eel-type skyrmions in Ta/CoFeB/MgO/Ta multilayers driven by propagating SAW pulses from on-chip piezoelectric transducers. Our results reveal that the elastic wave with longitudinal and shear vertical displacements (Rayleigh wave) traps skyrmions, while the shear horizontal wave effectively drives the motion of skyrmions. In particular, a longitudinal motion along the SAW propagation direction and a transverse motion due to topological charge, are observed and further confirmed by our micromagnetic simulations. This work demonstrates a promising approach based on acoustic waves for manipulating skyrmions, which could offer new opportunities for ultra-low power spintronics.