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Anisotropic conductivity in monolayer WTe<sub>2</sub>

ORAL

Abstract

The layered semimetal WTe2 behaves in the monolayer limit as a topological insulator but the nature of the insulating state in the interior bulk is unclear. We study its conductivity as a function of gate doping, temperature, and current direction. Care is needed to eliminate helical edge conduction from the measurements, including along cracks, which we locate by microwave impedance microscopy. The conductivity is found to be highly anisotropic for hole doping and much less so for electron doping. Surprisingly, for hole doping the conductivity is about three times lower along the a-axis, the direction of the tungsten chains, than along the b-axis, perpendicular to the chains. We consider the implications of this observation for the possibility that the state is a kind of excitonic insulator.

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Presenters

  • Bosong Sun

    University of Washington

Authors

  • Bosong Sun

    University of Washington

  • Paul Malinowski

    University of Washington

  • Zaiyao Fei

    Department of Physics, University of Washington, University of Washington

  • Tauno Palomaki

    Sandia National Laboratory, Sandia National Laboratories

  • Xiong Huang

    University of California, Riverside, Department of Physics and Astronomy, University of California, Riverside, University of California, Reverside

  • Elliott Runburg

    University of Washington

  • Yongtao Cui

    University of California, Riverside, Department of Physics and Astronomy, University of California, Riverside, University of California, Reverside

  • Jiun-Haw Chu

    University of Washington, Department of Physics, University of Washington, Seattle, Department of Physics, University of Washington, Physics, University of Washington

  • Xiaodong Xu

    Physics, University of Washington, Department of Physics, University of Washington, University of Washington, Department of Physics, University of Washington, Seattle, University of Washington, Seattle

  • David Cobden

    Department of Physics, University of Washington, University of Washington