Strain mediated transition between skyrmion and antiskyrmion in ferromagnetic thin films

Abstract

Magnetic topological structures have attracted great attention due to their potential applications in memory and logic devices. Achieving the controllable transition between different magnetic topological structures is crucial for their application. Here, we develop a phase field model with strain-modulated Dzyaloshinskii-Moriya interaction (DMI) and predict the controllable transitions between skyrmion and antiskyrmion states in a ferromagnetic thin film through the application of different strains. It is found that the anisotropic DMI induced by anisotropic strains in the thin film plays an important role in the transitions between various magnetic structures, including skyrmion, antiskyrmion, single domain, and helical domain. Anisotropic DMI also has a significant impact on the chirality and deformation of magnetic topological structures, among which anisotropic DMI can cause anisotropic deformation of skyrmions and antiskyrmions. Furthermore, the formation mechanism of antiskyrmions is elucidated by decomposing the magnetization vectors into Bloch and Néel-type components based on the Lifshitz invariant. This work not only provides an insight into the dynamic behaviors of topological structures but also suggests a new method for controlling magnetic configurations through strain engineering.