Topology-guided rotational dynamics of magnetic soliton assemblies under pulsed current.

Abstract

Emergent topological spin textures, such as nanometric skyrmions and antiskyrmions, not only exhibit a wealth of novel physical phenomena but also represent promising candidates for next-generation spintronic devices due to their topological stability and low-current-driven dynamics. Investigating their responses to electric currents is essential for uncovering unique electromagnetic properties and advancing their integration into electronic technologies. While considerable progress has been made through extensive research over the past decade, key challenges still persist. In this study, we demonstrate the novel, current-driven oppositely rotating dynamics of skyrmion and antiskyrmion assemblies in terms of Lorentz transmission electron microscopy. Their senses of rotation are strongly dictated by their inherent topological charges and remain largely unaffected by current direction, showing consistent behavior observed across various sample geometries. Further experimental analyses have revealed a reduction in angular velocity as (anti)skyrmions move away from the sample edge. The theoretical analyses, combined with micromagnetic simulations, highlight the critical roles of boundary-induced confining potentials and gyrotropic forces in steering the rotational dynamics of (anti)skyrmions. These findings offer new insights into current-driven (anti)skyrmion dynamics and open promising avenues for advancing topological concepts in confined spintronic systems.