Antiferromagnetic Skyrmion: Stability, Creation and Manipulation

TL;DR

This paper introduces the concept of antiferromagnetic skyrmions, demonstrating their stability, methods for creation, and straight-line manipulation, which could lead to new spintronic device designs without the skyrmion Hall effect.

Contribution

It proposes the existence of AFM skyrmions, details methods for their creation via simulations, and shows their potential for stable, straight-line motion in spintronic applications.

Findings

AFM skyrmions are topologically protected and do not exhibit the skyrmion Hall effect.

Two creation methods are demonstrated: spin-polarized current injection and domain-wall conversion.

AFM skyrmions can move straight over long distances under current drive.

Abstract

Magnetic skyrmions are particle-like topological excitations in ferromagnets, which have the topological number $Q=\pm 1$, and hence show the skyrmion Hall effect (SkHE) due to the Magnus force effect originating from the topology. Here, we propose the counterpart of the magnetic skyrmion in the antiferromagnetic (AFM) system, that is, the AFM skyrmion, which is topologically protected but without showing the SkHE. Two approaches for creating the AFM skyrmion have been described based on micromagnetic lattice simulations: (i) by injecting a vertical spin-polarized current to a nanodisk with the AFM ground state; (ii) by converting an AFM domain-wall pair in a nanowire junction. It is demonstrated that the AFM skyrmion, driven by the spin-polarized current, can move straightly over long distance, benefiting from the absence of the SkHE. Our results will open a new strategy on designing the novel spintronic devices based on AFM materials.