Observation of Quantum Anomalous Hall Effect and Exchange Interaction in Topological Insulator/Antiferromagnet Heterostructure

Published

August 27, 2020

Author(s)

Lei Pan, Alexander Grutter, Peng Zhang, Xiaoyu Che, Tomohiro Nozaki, Alex Stern, Mike Street, Bing Zhang, Brian Casas, Qing L. He, Eun S. Choi, Steven M. Disseler, Dustin Gilbert, Gen Yin, Qiming Shao, Peng Deng, Yingying Wu, Xiaoyang Liu, Xufeng Kou, Sahashi Masashi, Xiaodong Han, Christian Binek, Scott Chambers, Jing Xia, Kang L. Wang

Abstract

Integration of a quantum anomalous Hall insulator with a magnetically ordered material provides an additional degree of freedom through which we may control the resulting exotic quantum states. Here, we report an experimental observation of the quantum anomalous Hall effect in a magnetically-doped topological insulator grown on the antiferromagnetic insulator Cr₂O₃. We investigate the exchange coupling between the two materials using field-cooling-dependent magnetometry and polarized neutron reflectometry. Both techniques reveal strong interfacial interaction between the antiferromagnetic order of the Cr₂O₃ and the magnetic topological insulator, manifested as an exchange bias when the sample is field-cooled under an out-of-plane magnetic field, and an exchange spring-like magnetic depth profile when the system is magnetized within the film plane. Our results identify antiferromagnetic insulators as suitable candidates for the manipulation of magnetic and topological order in topological insulator films.

Citation

Advanced Materials

Volume

32

Pub Type

Journals

Keywords

Magnetism, topology, Quantum anomalous hall effect, topological insulator, antiferromagnet, thin film

Citation

Pan, L. , Grutter, A. , Zhang, P. , Che, X. , Nozaki, T. , Stern, A. , Street, M. , Zhang, B. , Casas, B. , He, Q. , Choi, E. , Disseler, S. , Gilbert, D. , Yin, G. , Shao, Q. , Deng, P. , Wu, Y. , Liu, X. , Kou, X. , Masashi, S. , Han, X. , Binek, C. , Chambers, S. , Xia, J. and Wang, K. (2020), Observation of Quantum Anomalous Hall Effect and Exchange Interaction in Topological Insulator/Antiferromagnet Heterostructure, Advanced Materials (Accessed December 10, 2024)