Topological Hall\nEffect in Bi/Cr<sub>2</sub>Te<sub>3</sub> Heterostructure Thin Films

The topological Hall effect (THE) due to the spatially\nvarying\nmagnetizations appears as humps and dips near the coercive field in\nthe Hall resistance curves. It is possible that magnetic skyrmions\nmight be applied to next-generation data storage devices. Previous\ncalculations predicted that the combination of Cr<sub>2</sub>Te<sub>3</sub> thin film with strong perpendicular anisotropy (PMA) and\nBi with strong spin–orbit coupling (SOC) could induce Dzyaloshinskii–Moriya\ninteraction (DMI) and magnetic skyrmions. THE has been observed in\nCr<sub>2</sub>Te<sub>3</sub> thin films with Bi bilayer nanosheets\nintercalated. However, the distribution of inserted Bi nanosheets\nwas random, therefore, locating and studying the interface between\nBi and Cr<sub>2</sub>Te<sub>3</sub> layers is difficult. The growth\nscheme of Bi on the Cr<sub>2</sub>Te<sub>3</sub> surface is still\nblank. In this work, Bi/Cr<sub>2</sub>Te<sub>3</sub> heterostructure\nthin films were fabricated by molecular beam epitaxy (MBE). The Bi\n(1 1 0) surface was grown on the Cr<sub>2</sub>Te<sub>3</sub> (0 0\n0 1) layer in islands from cross-sectional and plane-view scanning\ntransmission electron microscopy (STEM) observation. THE signals were\nobserved in the Bi/Cr<sub>2</sub>Te<sub>3</sub> heterostructure thin\nfilms below 130 K. The two-component anomalous Hall effect (AHE) that\nmight induce similar hump and dip signals near the coercive field\nwas excluded by the minor loop method.