Proximity-induced superconducting gap in the quantum spin Hall edge state of monolayer WTe<sub>2</sub>

ORAL

Abstract

Van der Waals heterostructures allow the combination of different material properties, e.g. non-trivial topology and superconductivity in order to create a topological superconducting state. In my talk, I demonstrate a novel dry-transfer flip technique which allows to place atomically-thin layers of WTe2, a quantum spin hall system, on NbSe2, a van der Waals superconductor. Using scanning tunneling microscopy and spectroscopy (STM/STS), we demonstrate atomically clean surfaces and interfaces and the presence of a proximity-induced superconducting gap in the WTe2 for thicknesses from a monolayer up to 7 crystalline layers. At the edge of the WTe2 monolayer, we show that the superconducting gap coexists with the characteristic spectroscopic signature of the QSH edge state [1]. Taken together, these observations provide conclusive evidence for proximity-induced superconductivity in the QSH edge state in WTe2, a crucial step towards realizing 1D topological superconductivity and Majorana states in this van der Waals material platform.

[1] F. Lüpke, et al., arXiv:1903.00493 (2019)

*This reasearch was funded by DOE DE-SC0018115, DOE DE-SC0014506, NSF DMR-1539916, NSF DMR-1809145, NSF DMR-1626099.

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Presenters

  • Felix Luepke

    • Carnegie Mellon University
    • Carnegie Mellon Univ
    • Oak Ridge National Lab

Authors

  • Felix Luepke

    • Carnegie Mellon University
    • Carnegie Mellon Univ
    • Oak Ridge National Lab

  • Dacen Waters

    • Physics Department, Carnegie Mellon University
    • Carnegie Mellon University
    • Carnegie Mellon Univ

  • Sergio de la Barrera

    • Massachusetts Institute of Technology MIT
    • Physics, Massachusetts Institute of Technology
    • Massachusetts Institue of Technology

  • Michael Widom

    • Carnegie Mellon Univ
    • Carnegie Mellon University
    • Physics, Carnegie-Mellon University, Pittsburgh, PA 15213, USA

  • David Mandrus

    • Physics, University of Tennessee
    • Materials Science and Engineering, The University of Tennessee
    • Department of Materials Science & Engineering, University of Tennessee, Knoxville
    • The University of Tennesse, Knoxville
    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennessee
    • Oak Ridge National Laboratory
    • Department of Materials Science and Engineering, University of Tennessee Knoxville
    • Department of Materials Science and Engineering, University of Tennessee
    • University of Tennessee, Knoxville
    • Material Science and Technology Division, Oak Ridge National Laboratory
    • Material Science and Technology Division, Oak Ridge National Lab

  • Jiaqiang Yan

    • Materials Science and Engineering, The University of Tennessee
    • Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Lab
    • Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

  • Randall M Feenstra

    • Physics Department, Carnegie Mellon University
    • Carnegie Mellon University
    • Carnegie Mellon Univ

  • Benjamin Hunt

    • Carnegie Mellon Univ
    • Physics Department, Carnegie Mellon University
    • Carnegie Mellon University
    • Department of Physics, Carnegie Mellon University