Paradoxical Topological Soliton Lattice in Anisotropic Frustrated Chiral Magnets

TL;DR

Scientists discovered a stable lattice of skyrmions and antiskyrmions in certain magnetic materials, which is surprising because these particles usually cancel each other out.

Contribution

A paradoxical skyrmion-antiskyrmion lattice with net-zero topological charge is shown to be a stable magnetic ground state in anisotropic frustrated chiral magnets.

Findings

A skyrmion-antiskyrmion lattice with balanced populations is shown to be a magnetic field-induced ground state.

The lattice has a net-zero global topological charge due to equal numbers of skyrmions and antiskyrmions.

2Fe/InSb(110) is identified as a promising material for realizing this phase.

Abstract

2D chiral magnets are known to host a variety of skyrmions, characterized by an integer topological charge (Q∈Z). However, these systems typically favor uniform lattices as thermodynamically stable phases composed of either skyrmions (Q = −1) or antiskyrmions (Q = 1). In isotropic chiral magnets, skyrmion‐antiskyrmion coexistence is typically transient due to mutual annihilation, making the observation of a stable, long‐range, ordered lattice a significant challenge. Here, this challenge is addressed by demonstrating a skyrmion‐antiskyrmion lattice as a magnetic field‐induced topological ground state in chiral magnets with competing anisotropic interactions, specifically Dzyaloshinskii‐Moriya and frustrated exchange interactions. This unique lattice exhibits a net‐zero global topological charge due to the balanced populations of skyrmions and antiskyrmions. Furthermore, density functional theory and spin‐lattice simulations identify 2Fe/InSb(110) as an ideal candidate material for realizing this phase. This finding reveals new possibilities for manipulating magnetic solitons and establishes anisotropic frustrated chiral magnets as a promising material class for future spintronic applications.

The article describes the discovery of a stable skyrmion‐antiskyrmion lattice (S‐AL) in anisotropic frustrated chiral magnets. This lattice has a net‐zero topological charge due to a balanced population of skyrmions and antiskyrmions. This is a paradoxical finding since these particles normally annihilate each other. The S‐AL phase emerges as a magnetic field induced ground state, revealing new possibilities for manipulating magnetic solitons.

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