Stabilization of skyrmions in two-dimensional systems with next-nearest-neighbor exchange interactions

Abstract

We study, in the absence of a magnetic field, the stabilization of skyrmions in a single-layered ferromagnet in the presence of next-nearest-neighbor exchange interactions including both the ferromagnetic exchange interaction and Dzyaloshinskii–Moriya exchange interaction. The stabilization of skyrmion depends on not only magnetic anisotropy but also the next-nearest-neighbor ferromagnetic exchange interaction. The latter stabilizes bimeron in the presence of in-plane magnetic anisotropy, while it enhances the stabilization of the ferromagnetic background in the presence of perpendicular magnetic anisotropy. Numerical simulations show that the next-nearest-neighbor ferromagnetic exchange interaction is a viable tool to control the creation and annihilation of skyrmionic states with a small size. This study may open an alternative avenue to the generation, stabilization, and control of magnetic skyrmions in the two-dimensional thin films.