Observation of the Quantum-Anomalous-Hall Insulator to Anderson Insulator Quantum Phase Transition in Magnetic Topological Insulators

ORAL

Abstract

The quantum anomalous Hall (QAH) effect can be considered as the quantum Hall (QH) effect without external magnetic field, which can be realized by time reversal symmetry breaking in a topologically non-trivial system [1,2], and in thin films of magnetically-doped TI [3]. A QAH system carries spin-polarized dissipationless chiral edge transport channels without the need for external energy input, hence may have huge impact on future electronic and spintronic device applications for ultralow-power consumption. The observation of QAH effect has opened up exciting new physics and thus understanding the physical nature of this novel topological quantum state, can lead to a rapid development of this field. In this talk, we will report our recent progress about the experimental observation of a quantum phase transition from a quantum-anomalous-Hall (QAH) insulator to an Anderson insulator by tuning the chemical potential, and finally discuss the existence of scaling behavior for this quantum phase transition. References [1] F. D. M. Haldane, Phys. Rev. Lett. 61, 2015-2018 (1988). [2] R. Yu et al, Science 329, 61-64 (2010). [3] C. Z. Chang et al, Science 340, 167(2013); Nature Materials 14, 473(2015).

*Work Supported by funding from NSF (DMR-1207469), NSF (DMR-0819762) (MIT MRSEC), ONR (N00014-13-1-0301), and the STC Center for Integrated Quantum Materials under NSF grant DMR-1231319.

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Authors

  • Cui-Zu Chang

    • Massachusetts Institute of Technology, Pennsylvania State University
    • The Penn State University & Massachusetts Institute of Technology
    • MIT&The Penn State University
    • Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139
    • Francis Bitter Magnet Lab, Massachussetts Institute of Technology, Cambridge, MA 02139

  • Wei-Wei Zhao

    • The Penn State University

  • Jian Li

    • Princeton University

  • Jainendra K. Jain

    • Pennsylvania State University
    • The Penn State University
    • Pennsylvania State Univ

  • Chaoxing Liu

    • The Penn State University

  • J.S. Moodera

    • Dept. of Physics, Francis Bitter Magnet Lab, Plasma Science and Fusion Center, MIT
    • Massachusetts Institute of Technology
    • Dept. of Physics and Francis Bitter Magnet Lab, MIT
    • MIT
    • Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139
    • Francis Bitter Magnet Lab, Massachussetts Institute of Technology, Cambridge, MA 02139

  • Moses H. W. Chan

    • Pennsylvania State University
    • The Penn State University