Scanning Tunneling Spectroscopy of 2D Topological Insulators

ORAL

Abstract

2D topological insulators (TIs) are an exciting new class of material, wherein band inversion in the bulk leads to topologically protected gapless edge modes. In WTe$_{2}$ and ZrTe$_{5}$, two potential 2D TIs we are studying, these edge modes are confined to within tens of nanometers of the edge of the sample. Scanning tunneling spectroscopy (STS) should provide a powerful probe of these modes, and open opportunities to study the effects of gating and proximity effect due to layered superconductors, such as NbSe$_{2}$ and FeSeTe, in contact with the 2D TIs. However, these measurements require extremely clean surfaces and interfaces, protection of these sensitive materials from oxidation, and the ability to position the tip accurately on the substrate. To satisfy these requirements and allow STS, we must prepare everything away from air and encapsulate in monolayer hBN. We present our progress in developing these techniques, and some preliminary measurements.

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Authors

  • Joshua Kahn

    Department of Physics, University of Washington, Univ of Washington

  • Paul Nguyen

    Univ of Washington, Department of Physics, University of Washington, University of Washington

  • Bosong Sun

    Univ of Washington, Department of Physics, University of Washington, University of Washington

  • Tauno Palomaki

    Univ of Washington, University of Washington

  • Jiun-Haw Chu

    Univ of Washington, University of Washington, Stanford University and University of Washington

  • David Cobden

    Department of Physics, University of Washington, Department of Physics, University of Washington, Seattle, WA 98195, USA, Univ of Washington, University of Washington