Matryoshka Skyrmions

TL;DR

This paper introduces a novel hierarchical structure of stable Skyrmions in higher dimensions, constructed as nested solitons within domain walls in O(N) sigma models, without relying on the Skyrme term.

Contribution

It demonstrates the existence of stable, nested Skyrmions in higher dimensions using hierarchical mass terms and non-Abelian domain walls, expanding the understanding of topological solitons.

Findings

Stable 3+1D Skyrmion as sine-Gordon kink inside a domain wall

Higher-dimensional Skyrmions stabilized by non-Abelian domain walls

Matryoshka structure of nested Skyrmions

Abstract

We construct a stable Skyrmion in 3+1 dimensions as a sine-Gordon kink inside a domain wall within a domain wall in an O(4) sigma model with hierarchical mass terms without the Skyrme term. We also find that higher dimensional Skyrmions can stably exist with a help of non-Abelian domain walls in an O(N) model with hierarchical mass terms without a Skyrme term, which leads a matryoshka structure of Skyrmions.