Observation of nonlinear planar Hall effect in magnetic-insulator–topological-insulator heterostructures

Interfacing topological insulators (TIs) with magnetic (MIs) has been widely used to study the interaction between surface states and magnetism. Previous transport studies typically interpret suppression of weak antilocalization or appearance anomalous Hall effect as signatures proximity (MPE) imposed TIs. Here, we report observation nonlinear planar (NPHE) in Bi2Se3 films grown on MI thulium yttrium iron garnet (TmIG YIG) substrates, which is an order magnitude larger than that nonmagnetic gadolinium gallium (GGG) substrate. The resistance TmIG/Bi2Se3 depends linearly external field, while YIG/Bi2Se3 exhibits extra hysteresis loop around zero field. NPHE found scale inversely carrier density. We speculate observed related MPE-induced exchange gap opening out-of-plane spin textures TI states, may be alternative signature MPE MI/TI heterostructures.