Domain Wall Skyrmions in Chiral Magnets

TL;DR

This paper analytically investigates domain wall skyrmions in chiral magnets, revealing their stability and behavior within domain walls using a sine-Gordon model derived from the low-energy effective theory.

Contribution

It provides an analytic construction of domain wall skyrmions as sine-Gordon solitons, highlighting their unique stability properties inside domain walls in chiral magnets.

Findings

Both skyrmions and anti-skyrmions are equally stable inside the domain wall.

Constructed domain wall skyrmions on top of a pair of domain and anti-domain walls.

Developed a low-energy effective theory using a sine-Gordon model.

Abstract

Domain wall skyrmions are skyrmions trapped inside a domain wall. We investigate domain wall skyrmions in chiral magnets using a fully analytic approach. Treating the Dzyaloshinskii-Moriya (DM) interaction perturbatively, we construct the low-energy effective theory of a magnetic domain wall in an $O(3)$ sigma model with the DM interaction and an easy-axis potential term, yielding a sine-Gordon model. We then construct domain wall skyrmions as sine-Gordon solitons along the domain wall. We also construct domain wall skyrmions on top of a pair of a domain wall and an anti-domain wall. One of characteristic feature of domain wall skyrmions is that both skyrmions and anti-skyrmions are equally stable inside the domain wall, unlike the bulk in which only one of them is stable.