Spin Scattering and Noncollinear Spin Structure-Induced Intrinsic Anomalous Hall Effect in Antiferromagnetic Topological Insulator MnBi2Te4

Published

August 19, 2019

Author(s)

Seng Huat Lee, Yanglin Zhu, Yu Wang, Leixin Miao, Timothy Pillsbury, Hemian Yi, Susan Kempinger, Jin Hu, Colin A. Heikes, Patrick Quarterman, William D. Ratcliff, Julie Borchers, Heda Zhang, Xianglin Ke, David Graf, Nasim Alem, Cui-Zu Chang, Nitin Samarth, Zhiqiang Mao

Abstract

MnBi₂Te₄ has recently been established as an intrinsic antiferromagnetic (AFM) topological insulator - an ideal platform to create quantum anomalous Hall (QAH) insulator and axion insulator states. We performed comprehensive studies on the structure, nontrivial surface state and magnetotransport properties of this material. Our results reveal an intrinsic anomalous Hall effect arising from a non-collinear spin structure for the magnetic field parallel to the c-axis. We also observed remarkable negative magnetoresistance under arbitrary field orientation below and above the Neel temperature (T_N), providing clear evidence for strong spin fluctuation-driven spin scattering in both the AFM and paramagnetic states. Furthermore, we found that the nontrivial surface state opens a large gap (85meV) even far above T_N. These findings demonstrate that the bulk band structure of MnBi₂Te₄ is strongly coupled with the magnetic structure and that a net Berry curvature in momentum space can be created in a canted AFM state. In addition, our results imply that the gap opening in the surface states is intrinsic, likely caused by the strong spin fluctuations near the surface layers.

Citation

Physical Review Research

Volume

1

Issue

1

Pub Type

Journals

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Keywords

Topological Insulators, Magnetism, Neutron Scattering

Citation

Lee, S. , Zhu, Y. , Wang, Y. , Miao, L. , Pillsbury, T. , Yi, H. , Kempinger, S. , Hu, J. , Heikes, C. , Quarterman, P. , Ratcliff, W. , Borchers, J. , Zhang, H. , Ke, X. , Graf, D. , Alem, N. , Chang, C. , Samarth, N. and Mao, Z. (2019), Spin Scattering and Noncollinear Spin Structure-Induced Intrinsic Anomalous Hall Effect in Antiferromagnetic Topological Insulator MnBi₂Te₄, Physical Review Research, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928072 (Accessed November 22, 2024)