Probing the Nature of Residual Dissipation in the Quantum Anomalous Hall Effect

ORAL

Abstract

Recently, quantization of the Hall resistance in the quantum anomalous Hall effect (QAHE) in magnetic topological insulators has been demonstrated with record precision [1,2] at dilution refrigerator temperatures and currents under 100 nA. To further improve quantization for using the QAHE in resistance metrology and other technological applications where performance at higher currents and temperatures is required, it will be important to understand the sources of dissipation in this system. Using transport measurements of Cr-(Bi,Sb)2Te3 thin films, we investigate the effects of temperature, current, and chemical potential to provide new clues about non-ideal behavior in the QAHE. In particular, we discuss whether dissipative transport occurs at the sample edges or in the 2D bulk, the interplay of thermally activated and variable-range hopping conduction, and the nature of the current-induced breakdown [1,3] of the QAHE.

[1] E. J. Fox, et al., arXiv:1710.01850.
[2] M. Goetz, et al., arXiv:1710.04090.
[3] M. Kawamura, et al., Phys. Rev. Lett. 119, 016803 (2017).

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Presenters

  • Eli Fox

    Department of Physics, Stanford University, Stanford University, Physics, Stanford University

Authors

  • Eli Fox

    Department of Physics, Stanford University, Stanford University, Physics, Stanford University

  • Ilan Rosen

    Department of Applied Physics, Stanford University, Stanford University, Applied Physics, Stanford University

  • David Goldhaber-Gordon

    Department of Physics, Stanford University, Stanford University, Physics, Stanford University, Stanford Univ

  • Lei Pan

    Univ of California - Los Angeles, Department of Electrical Engineering, University of California, Los Angeles, University of California Los Angeles, UCLA, Electrical Engineering, UCLA

  • Xufeng Kou

    School of Information Science and Technology, ShanghaiTech University, ShanghaiTech University, UCLA

  • Kang Wang

    University of California, Los Angeles, Univ of California - Los Angeles, Department of Electrical Engineering, University of California, Los Angeles, Department of Electrical Engineering, UCLA, University of California Los Angeles, UCLA, Department of Electrical Engineering, Univ of California - Los Angeles, Electrical and Computer Engineering, University of California, Los Angeles, Electrical Engineering, UCLA