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

Novel magnetic and electric phenomena could emerge in perovskite oxide heterostructures due to multiple and complex coupling at the hetero-interface. Here, we report that an emergent giant topological Hall effect (THE) can be induced in ferromagnetic La_0.7Sr_0.3MnO₃ thin films in a wide temperature range up to 200 K by constructing La_0.7Sr_0.3MnO₃/SrIrO₃ epitaxial heterostructures. The observed THE indicates a non-coplanar spin texture, which also leads to strongly pinched field dependent magnetization (MH) loops in the out-of-plane direction. This THE and pinched MH loops are not observed in La_0.7Sr_0.3MnO₃ single layer films or La_0.7Sr_0.3MnO₃/SrTiO₃/SrIrO₃ trilayer heterostructures, indicating the relevance of the La_0.7Sr_0.3MnO₃/SrIrO₃ interface, where Dzyaloshinskii-Moriya interaction due to strong spin-orbital coupling in SrIrO₃ may play a crucial role. This work demonstrates the feasibility of using SrIrO₃ to modify magnetic and transport characteristics by interfacing with other correlated oxides, which might be useful to novel spintronic applications.