Topological Hall effect in multilayers

Abstract

Physics Skyrmions—topologically protected whirlpools of spin—are a candidate for information processing in magnetic materials. In early work, skyrmions were found in bulk materials at relatively low temperatures. More recently, room temperature skyrmions have been detected in thin multilayers, but understanding their behavior is tricky, thanks to a combination of complex electronic structure, disorder, and interfacial effects. Raju et al. used two complementary techniques—magnetic force microscopy and Hall transport—to tease out how skyrmions affect charge transport in these multilayers. The number of skyrmions seen through microscopy scaled with the topological contribution to the Hall effect, but a quantitative agreement between the results of the two probes requires taking into account interactions between skyrmions and the detailed properties of the system. Nat. Commun. 10, 696 (2019).