single-layered thin films

Topology in condensed matter physics has led to fruitful areas such as topological insulators, Majorana fermions and valleytronics. Among them, the topological Hall effect (THE) of magnetic materials has attracted much attention due to the discovery of magnetic skyrmions, a topologically protected spin texture that is promising for future magnetic/electronic devices. Recently, a THE has been observed at the interface between a ferromagnetic SrRuO₃ (SRO) and a heavy metal SrIrO₃ (SIO), although the spin texture of both bulk SRO and bulk SIO are topologically trivial. Here, we will demonstrate the discovery of an unexpected THE on perovskite SRO single-layered films stabilized by molecular beam epitaxy. We will show that the epitaxial strain in SRO films stabilizes a non-coplanar spin texture and leads to the topologically non-trivial phenomenon. SRO is a widely-used material in complex oxide heterostructures. Our results can potentially lead to major progresses in novel phenomena in SRO-based heterostructures as well as the applications of next generation all-oxide electronic and magnetic devices.