Observation of topological Hall effect in synthetic antiferromagnetic skyrmion system

Abstract

Synthetic antiferromagnetic (SAF) skyrmions have emerged as promising candidates for next-generation high-speed and highly integrated spintronic devices owing to their exceptional properties, such as high driving velocity, nanoscale dimensions, and the absence of the skyrmion Hall effect. In this work, we report the experimental observation of the topological Hall effect in both compensated and non-compensated SAF skyrmion systems based on the [Pt/Co/Ru]2 trilayer. The antiferromagnetic skyrmions are further demonstrated to be robust in these SAFs under zero field. Our first-principles calculations, atomistic spin model simulations, and transmission electron microscopy measurements show that the observed topological Hall Effect is related to the skyrmion structures in the Ru and Pt layers, which are induced by the magnetic proximity effect and atomic diffusion. This work examines the role of the magnetic proximity effect in the topological Hall effect of SAF skyrmions in these systems.