Observation of Chiral Transport along Magnetic Domain Walls in a Quantum Anomalous Hall Insulator

ORAL

Abstract

The quantum anomalous Hall (QAH) effect, which has been realized in thin films of ferromagnetic topological insulators, features a single chiral edge mode that circles the boundary of the film, similarly to the ν=1 quantum Hall (QH) system. Unlike QH, the chirality of the QAH edge mode is determined by the film's magnetization, not by the external magnetic field. Magnetic domain walls in QAH insulators therefore form adjacent QAH systems of opposite chirality; dissipationless chiral conduction is expected along such magnetic domain walls[1,2]. Using Meissner screening to locally modulate the applied magnetic field, we intentionally form a magnetic domain wall in Cr-(Bi,Sb)2Te3[3]. We then use transport measurements to verify that conduction along magnetic domain walls is chiral and nearly dissipationless.

[1] R. Wakatsuki, M. Ezawa, and N. Nagaosa, Sci. Rep. 5, 13638 (2015).
[2] P. Upadhyaya and Y. Tserkovnyak, Phys. Rev. B 94, 020411 (2016).
[3] I. T. Rosen et al., Nat. Quantum Mater. (accepted, 2017), arXiv:1707.08677.

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Presenters

  • Ilan Rosen

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

Authors

  • Ilan Rosen

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

  • Eli Fox

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

  • 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

  • David Goldhaber-Gordon

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