Experimental Observation of the Gate-Controlled Reversal of the Anomalous Hall Effect in the Intrinsic Magnetic Topological Insulator MnBi2Te4 Device

Shuai Zhang; Rui Wang; Xuepeng Wang; Boyuan Wei; Bo Chen; Huaiqiang Wang; Gang Shi; Feng Wang; Bin Jia; Yiping Ouyang; Faji Xie; Fucong Fei; Minhao Zhang; Xuefeng Wang; Di Wu; Xiangang Wan; Fengqi Song; Haijun Zhang; Baigeng Wang

doi:10.1021/acs.nanolett.9b04555

Experimental Observation of the Gate-Controlled Reversal of the Anomalous Hall Effect in the Intrinsic Magnetic Topological Insulator MnBi₂Te₄ Device

Nano Lett. 2020 Jan 8;20(1):709-714. doi: 10.1021/acs.nanolett.9b04555. Epub 2019 Dec 17.

Authors

Shuai Zhang¹, Rui Wang^{1

2}, Xuepeng Wang¹, Boyuan Wei¹, Bo Chen¹, Huaiqiang Wang¹, Gang Shi³, Feng Wang¹, Bin Jia¹, Yiping Ouyang¹, Faji Xie¹, Fucong Fei¹, Minhao Zhang¹, Xuefeng Wang⁴, Di Wu¹, Xiangang Wan¹, Fengqi Song¹, Haijun Zhang¹, Baigeng Wang¹

Affiliations

¹ National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics , Nanjing University , Nanjing 210093 , China.
² Department of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China.
³ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China.
⁴ National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China.

PMID: 31838853
DOI: 10.1021/acs.nanolett.9b04555

Abstract

Magnetic topological insulator, a platform for realizing quantum anomalous Hall effect, axion state, and other novel quantum transport phenomena, has attracted a lot of interest. Recently, it is proposed that MnBi₂Te₄ is an intrinsic magnetic topological insulator, which may overcome the disadvantages in the magnetic doped topological insulator, such as disorder. Here we report on the gate-reserved anomalous Hall effect (AHE) in the MnBi₂Te₄ thin film. By tuning the Fermi level using the top/bottom gate, the AHE loop gradually decreases to zero and the sign is reversed. The positive AHE exhibits distinct coercive fields compared with the negative AHE. It reaches a maximum inside the gap of the Dirac cone, and its amplitude exhibits a linear scaling with the longitudinal conductance. The positive AHE is attributed to the competition of the intrinsic Berry curvature and the extrinsic skew scattering. Its gate-controlled switching contributes a scheme for the topological spin field-effect transistors.

Keywords: Berry curvature; Magnetic topological insulator; anomalous Hall effect; sign reversal; skew scattering.