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

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.