Current-driven dynamics of antiferromagnetic domain-wall skyrmions

Abstract

Domain-wall skyrmions are magnetic solitons embedded in a domain wall that are topologically equivalent to skyrmions. Here, we theoretically study antiferromagnetic domain-wall skyrmions and their current-driven motion within the Landau-Lifshitz-Gilbert phenomenology, and verify our findings with micromagnetic simulations. While the skyrmion Hall effect is expected to be suppressed in the current-induced motion of antiferromagnetic domain-wall skyrmions, we observe a finite Hall angle, which originates from the anisotropic spin configuration of domain-wall skyrmions. The skyrmion Hall effect is, however, conditionally suppressed and the motion aligns with the current applied in certain directions, which can be interpreted as principal axes of a domain-wall skyrmion that is easily identified from the symmetry of the spin configuration. Our work on antiferromagnetic domain-wall skyrmions shows that the dynamics of spin textures endowed with multiple soliton characteristics can be unconventional, which is envisaged to enrich the field of topological solitons.