Emergent\nTopological Hall Effect in La_0.7Sr_0.3MnO₃/SrIrO₃ Heterostructures

Abstract

Recently, perovskite oxide heterostructures have drawn great attention\nbecause multiple and complex coupling at the heterointerface may produce\nnovel magnetic and electric phenomena that are not expected in homogeneous\nmaterials either in the bulk or in films. In this work, we report\nfor the first time that an emergent giant topological Hall effect\n(THE), associated with a noncoplanar (NC) spin texture, can be induced\nin ferromagnetic (FM) La_0.7Sr_0.3MnO₃ thin films in a wide temperature range of up to 200 K by constructing\nLa_0.7Sr_0.3MnO₃/SrIrO₃ epitaxial\nheterostructures on (001) SrTiO₃ substrates. This THE is\nnot observed in La_0.7Sr_0.3MnO₃ single-layer\nfilms or La_0.7Sr_0.3MnO₃/SrTiO₃/SrIrO₃ trilayer heterostructures, indicating the\nrelevance of the La_0.7Sr_0.3MnO₃/SrIrO₃ interface, where the Dzyaloshinskii–Moriya interaction\ndue to strong spin–orbital coupling in SrIrO₃ may\nplay a crucial role. The fictitious field associated with THE is independent\nof temperature in La_0.7Sr_0.3MnO₃/SrIrO₃ heterostructures, suggesting that the NC spin texture may\nbe magnetic skyrmions. This work demonstrates the feasibility of using\nSrIrO₃ to generate novel magnetic and transport characteristics\nby interfacing with other correlated oxides, which might be useful\nto novel spintronic applications.