Magnetic skyrmion dynamics induced by surface acoustic waves

Abstract

Magnetic skyrmions are promising information carriers for high-density memories. The dynamical motion of magnetic skyrmions have been extensively investigated in the development of magnetic racetracks. In this study, a surface acoustic wave (SAW) is theoretically investigated to drive skyrmions by using micromagnetic simulations. The in-plane type and out-of-plane particle displacement components of SAWs generate different magnetoelastic effective fields. The shear horizontal (SH) wave mode SAW drives skyrmions flow movement by the magnetoelastic coupling effect. Increasing the acoustic wave amplitude and magnetoelastic coupling constants, as well as a reduced wavelength, are beneficial for an enhanced skyrmion motion velocity. The skyrmion motion trajectory can be controlled by designing the geometry of magnetic films. Interestingly, in a circular magnetic film, the skyrmions driven by SH waves show clockwise or counterclockwise movement trajectories depending on the sign of topological charges. Our results provide an energy efficient approach to drive skyrmion dynamics including rotational motion, thus paving the way for low-power spintronics.