Logarithmic voltage bias dependence in ferromagnetic two-dimensional topological insulators

ORAL

Abstract

The quantum anomalous Hall effect has recently been demonstrated in thin films of $(\text{BiSb})_2\text{Te}_3$ with Vanadium doping. We report the first e-beam lithographically defined devices from this ferromagnetic two-dimensional topological insulator. Transport measurements show that, when the bulk is gated into a conducting state, longitudinal resistance and Hall resistance have logarithmic dependence on source-drain voltage bias and temperature. As this system may be a suitable platform for Majorana fermions, it is critical to understand the logarithmic dependence as it occurs around zero bias. We present a model to explain the observed logarithmic dependence near zero bias and address other sources of logarithmic dependence that are not present in the device.

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Authors

  • J. Ward

    • Department of Physics, Harvard University, Cambridge, MA, 02138
    • Department of Physics, Harvard University, Cambridge, MA 02138

  • K. Shain

    • Department of Physics, Harvard University, Cambridge, MA, 02138
    • Department of Physics, Harvard University, Cambridge, MA 02138

  • D. Nandi

    • Harvard University
    • Department of Physics, Harvard University, Cambridge, MA, 02138
    • Department of Physics, Harvard University, Cambridge, MA 02138

  • G.H. Lee

    • Harvard University, Cambridge, USA
    • Department of Physics, Harvard University, Cambridge, MA, 02138
    • Department of Physics, Harvard University, Cambridge, MA 02138

  • 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

  • K. Huang

    • Department of Physics, Harvard University, Cambridge, MA, 02138
    • Department of Physics, Harvard University, Cambridge, MA 02138

  • 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

  • P. Kim

    • Harvard University
    • Department of Physics, Harvard University
    • Department of Physics, Harvard University, Cambridge, MA 02138, US
    • Harvard University, department of Physics
    • Harvard University, Department of Physics
    • Department of Physics, Harvard University, Cambridge, MA, 02138
    • Department of Physics, Harvard University, Cambridge, MA 02138

  • A. Yacoby

    • Harvard University
    • Harvard University, Cambridge USA.
    • Department of Physics, Harvard University
    • Department of Physics, Harvard University, Cambridge, MA, 02138
    • Department of Physics, Harvard University, Cambridge, MA 02138