Electric control of a canted-antiferromagnetic Chern insulator

ORAL

Abstract

Nontrivial band topology and magnetic order meet in a topological magnet to produce novel topological phase of matters, such as quantum anomalous Hall insulator. While prior works have focused on ferromagnetic systems, little is known about band topology and its manipulation in antiferromagnets. Here, we report that MnBi2Te4 realizes a canted-antiferromagnetic (cAFM) Chern insulator with electrical control. We show that the Chern insulator state with C = 1 appears as soon as the AFM to canted-AFM phase transition happens. Near the phase boundary of cAFM and AFM phases, an electric field can switch the transport between dissipative or dissipationless transport. Our dual-gated RMCD measurement rules out magnetoelectric effects as the tuning mechanism and suggests a picture that electric field controls the relative alignment of the magnetic exchange gap between top and bottom surfaces.  

*The electrical control of Chern number in the canted antiferromagnetic states was mainly supported by AFOSR FA9550-21-1-0177. Magneto-optical measurements and theory understanding were partially supported as part of Programmable Quantum Materials, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award DE-SC0019443. The authors also acknowledge the use of the facilities and instrumentation supported by NSF MRSEC DMR-1719797. J.Y. acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. C.Z.C. acknowledges the partial support from the Gordon and Betty Moore Foundation’s EPiQS Initiative (Grant GBMF9063). Y.T.C. acknowledges support from NSF under award DMR-2004701 and the Hellman Fellowship award. X.X. and J.H.C. acknowledge the support from the State of Washington funded Clean Energy Institute.

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Publication: Cai, Jiaqi, et al. "Electric control of a canted-antiferromagnetic Chern insulator." arXiv preprint arXiv:2107.04626 (2021).

Presenters

  • Jiaqi Cai

    • University of Washington

Authors

  • Jiaqi Cai

    • University of Washington

  • Dmitry Ovchinnikov

    • University of Washington

  • Zaiyao Fei

    • University of Washington

  • Minhao He

    • University of Washington

  • Tiancheng Song

    • University of Washington
    • Princeton University

  • Zhong Lin

    • University of Washington

  • Chong Wang

    • Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
    • Carnegie Mellon Univ
    • University of Washington
    • University of Washington, Seattle
    • Carnegie Mellon University

  • David H Cobden

    • University of Washington

  • Jiun-Haw Chu

    • University of Washington

  • Yongtao Cui

    • University of California, Riverside

  • Cui-Zu Chang

    • Pennsylvania State University

  • Di Xiao

    • Carnegie Mellon Univ
    • University of Washington

  • Jiaqiang Yan

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • ORNL

  • Xiaodong Xu

    • University of Washington