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.

–

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