Dynamics of an Insulating Skyrmion under a Temperature Gradient

TL;DR

This paper investigates the counterintuitive movement of insulating Skyrmions towards higher temperatures under a gradient, combining numerical simulations and magnon-based theory to explain the phenomenon and suggest experimental observability.

Contribution

It introduces a magnon-based theoretical explanation for Skyrmion motion under temperature gradients, highlighting the role of topological charge and transverse motion.

Findings

Skyrmions move towards higher temperature regions, contrary to diffusion.

Theoretical predictions align with numerical simulations.

Potential for experimental observation of the Skyrmion dynamics.

Abstract

We study the Skyrmion dynamics in thin films under a temperature gradient. Our numerical simulations show that both single and multiple Skyrmions in a crystal move towards the high temperature region, which is contrary to particle diffusion. Noticing a similar effect in the domain wall motion, we employ a theory based on magnon dynamics to explain this counterintuitive phenomenon. Unlike the temperature driven domain wall motion, the Skyrmion's topological charge plays an important role, and a transverse Skyrmion motion is observed. Our theory turns out to be in agreement with numerical simulations, both qualitatively and quantitatively. Our calculation indicated that a very promising Skyrmion dynamic phenomenon can be observed in experiments.