Tunable surface configuration of skyrmion lattices in cubic helimagnets

TL;DR

This paper analytically describes how skyrmion lattices in cubic helimagnets induce a tunable, periodic surface displacement pattern that can be controlled by external fields, revealing a particle-like surface property.

Contribution

It provides the first analytical solution for the surface displacement field caused by skyrmion lattices in cubic helimagnets and demonstrates how this pattern can be externally tuned.

Findings

Skyrmion lattices create a periodic surface displacement pattern.

The surface peaks have a height of about 10^{-13} meters.

The surface configuration can be controlled by magnetic and electric fields.

Abstract

In bulk helimagnets, the presence of magnetic skyrmion lattices is always accompanied by a periodic stress field due to the intrinsic magnetoelastic coupling. The release of this nontrivial stress field at the surface causes a periodic displacement field, which characterizes a novel particle-like property of skyrmion: its surface configuration. Here, we derive the analytical solution of this displacement field for semi-infinite cubic helimagnets when skyrmions are present. For MnSi, we show that the skyrmion lattices have a bumpy surface configuration characterized by periodically arranged peaks with a characteristic height of about 10$^{-13}$ m. The pattern of the peaks can be controlled by varying the strength of the applied magnetic field. Moreover, we prove that the surface configuration varies together with the motion and deformation of the skyrmion lattices. As a result, the surface configuration can be tuned by application of electric current, mechanical loads, as well as any other form of external field which has an effect on the skyrmions.