Skyrmion states in thin confined polygonal nanostructures

TL;DR

This study demonstrates that skyrmionic states can be the ground state in thin, confined polygonal FeGe nanostructures without external magnetic fields, expanding understanding beyond cylindrical geometries.

Contribution

It shows that skyrmionic states are stable in square and triangular nanostructures, not just cylindrical ones, through simulation and provides data for experimental verification.

Findings

Skyrmionic states form the ground state in polygonal nanostructures.

Stable skyrmions exist without applied magnetic fields.

Simulation data supports experimental efforts.

Abstract

Recent studies have demonstrated that skyrmionic states can be the ground state in thin-film FeGe disk nanostructures in the absence of a stabilising applied magnetic field. In this work, we advance this understanding by investigating to what extent this stabilisation of skyrmionic structures through confinement exists in geometries that do not match the cylindrical symmetry of the skyrmion -- such as as squares and triangles. Using simulation, we show that skyrmionic states can form the ground state for a range of system sizes in both triangular and square-shaped FeGe nanostructures of $10\,\text{nm}$ thickness in the absence of an applied field. We further provide data to assist in the experimental verification of our prediction; to imitate an experiment where the system is saturated with a strong applied field before the field is removed, we compute the time evolution and show the final equilibrium configuration of magnetization fields, starting from a uniform alignment.