Dynamics of distorted skyrmions in strained chiral magnets

TL;DR

This paper investigates the anisotropic dynamics of distorted skyrmions in strained chiral magnets under external stimuli, revealing periodic velocity dependence and harmonic vibrations, supported by simulations and Thiele theory.

Contribution

It introduces a detailed simulation study of distorted skyrmion dynamics in strained chiral magnets, highlighting anisotropic responses and vibrational behaviors not previously characterized.

Findings

Skyrmion velocities depend periodically on stimulus direction.

Distorted skyrmions exhibit anti-phase harmonic vibrations.

Results align with Thiele theory predictions.

Abstract

In this work, we study the microscopic dynamics of distorted skyrmions in strained chiral magnets [K. Shibata et al., Nat. Nanotech. 10, 589 (2015)] under gradient magnetic field or electric current by Landau-Lifshitz-Gilbert simulations of the anisotropic spin model. It is observed that the dynamical responses are also anisotropic, and the velocities of the distorted skyrmions are periodically dependent on the directions of the external stimuli. Furthermore, in addition to the uniform motion, our work also demonstrates anti-phase harmonic vibrations of the two skyrmions in nanostripes, and the frequencies are mainly determined by the exchange anisotropy. The simulated results are well explained by Thiele theory, which may provide useful information in understanding the dynamics of the distorted skyrmions in strained chiral magnets.