Orientation-dependent current-induced motion of skyrmions with various topologies

Abstract

We study the current-driven motion of metastable localized spin structures with various topological charges in a (Pt0.95Ir0.05)/Fe bilayer on a Pd(111) surface by combining atomistic spin model simulations with an approach based on the generalized Thiele equation. We demonstrate that besides a distinct dependence on the topological charge itself the dynamic response of skyrmionic structures with topological charges Q=-1 and Q=3 to a spin-polarized current exhibits an orientation dependence. We further show that such an orientation dependence can be induced by applying an in-plane external field, possibly opening up a different pathway to the manipulation of skyrmion dynamics.