Motion of a magnetic skyrmionium driven by acoustic wave

Abstract

A magnetic skyrmionium does not exhibit skyrmion Hall effect due to its special structure with zero topological charge, which has an advantage over a skyrmion in the application of tracetrack memory. With the development of straintronics, acoustic waves could remotely control the topological magnetic structures, including skyrmionium. In this work, the acoustic wave induced dynamics of a skyrmionium on a strip film is studied by means of micromagnetic simulations. The results show that the motion of a skyrmionium is significantly influenced by the magnetic damping, the amplitude, and the frequency of the acoustic wave. The skyrmionium tends to acquire higher velocity at larger amplitude of the acoustic wave and smaller magnetic damping. With the increase in the acoustic wave amplitude, the skyrmionium deforms and moves faster due to stronger magnetoelastic interaction. When the frequency increases from 1 to 15 GHz, the velocity of skyrmionium generally increases except for the velocity fluctuation caused by magnetization resonance at a few frequencies. This work suggests a mechanical way to drive the motion of magnetic skyrmioniums by acoustic waves, offering potential applications in future information memory devices.