Road to zero-field antiferromagnetic skyrmions in a frustrated AFM/FM heterostructure

TL;DR

This paper presents a method to stabilize antiferromagnetic skyrmions in a heterostructure by coupling an antiferromagnetic layer with a ferromagnetic layer, reducing or eliminating the need for external magnetic fields.

Contribution

It introduces a mechanism leveraging interlayer coupling and anisotropy to stabilize skyrmions without external magnetic fields in frustrated AFM/FM heterostructures.

Findings

Effective field from FM layer reduces external field requirement.

Zero external field stabilization via spontaneous FM order.

Complete elimination of external field for SkX phase in certain conditions.

Abstract

We demonstrate a mechanism of significant reduction, including complete elimination, of the external magnetic field required for the stabilization of a skyrmion lattice (SkX) phase in a frustrated triangular Heisenberg antiferromagnet (AFM) with the Dzyaloshinskii-Moriya interaction. It is achieved by coupling of such a AFM plane to a reference ferromagnetic (FM) layer, which generates an effective field cooperating with the external magnetic field. If the FM layer shows some axial single-ion anisotropy then the effective field can also be generated in zero external field due to a spontaneous FM long-range ordering. Then a sufficiently large interlayer coupling can fully substitute the external magnetic field and the SkX phase in the AFM layer can be stabilized even in zero external field.