Topological Hall effect in ferrimagnetic CoTb single layer

•Topological Hall effect (THE) is observed in ferrimagnetic CoTb single layer for the first time.•Most prominent THE is found near compensation composition or Hall transition temperature.•THE is closely related to anisotropic antiferromagnetic coupling between Co and Tb moments.•Magnetic bubble-like domain structure can be observed. Hall transport properties of single ferrimagnetic CoTb thin films were systematically studied. We report on the extraordinary Hall signals near the magnetization compensation point. The Hall “anomaly”, which is reminiscent of the Topological Hall effect (THE), is distinguished from the anomalous Hall effect (AHE) by fitting the overall Hall resistance signal. At the Hall anomaly regime, magnetic bubbles are observed by optical magnetometry. We propose the observed Hall anomalies originate from the noncollinear spin texture stabilized by Dzyaloshinskii–Moriya interaction (DMI), which is closely related to the anisotropic antiferromagnetic coupling between Co and Tb moments. The novel phenomena found in CoTb thin films broaden the physic understanding of THE and may stimulate on further studies of THE in amorphous materials.