Signatures of the topological s<sup>+-</sup> superconducting order parameter in the type-II Weyl semimetal T<sub>d</sub>-MoTe<sub>2</sub>

ORAL

Abstract

In its orthorhombic Td polymorph, MoTe2 is a type-II Weyl semimetal, where the Weyl fermions emerge at the boundary between electron and hole pockets. Non-saturating magnetoresistance (MR) and superconductivity were also observed in Td-MoTe2. Understanding the superconductivity in Td-MoTe2, which was proposed to be topologically non-trivial, is of eminent interest. I will report high-pressure muon spin rotation experiments probing the temperature-dependent magnetic penetration depth in Td-MoTe2 [1].
A substantial increase of the superfluid density and a linear scaling with the superconducting critical temperature Tc is observed under pressure. Moreover, the superconducting order parameter in Td-MoTe2 is determined to have 2-gap s-wave symmetry. We also exclude time reversal symmetry breaking in the superconducting state with zero-field μSR experiments. Considering the strong suppression of Tc in MoTe2 by disorder, we suggest that topologically nontrivial s+- state is more likely to be realized in MoTe2 than the topologically trivial s++ state.

[1] Z. Guguchia et. al., Nature Communications 8, 1082 (2017).

*Z. Guguchia gratefully acknowledges the financial support by the Swiss National Science Foundation (Early Postdoc Mobility SNFfellowship P2ZHP2-161980).

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Presenters

  • Zurab Guguchia

    • Columbia Univ
    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute
    • Department of Physics, Columbia university

Authors

  • Zurab Guguchia

    • Columbia Univ
    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute
    • Department of Physics, Columbia university

  • Fabian von Rohr

    • Department of Chemistry, Princeton University

  • Zurab Shermadini

    • Paul Scherrer Institute
    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute

  • Alex Taekyung Lee

    • Department of Applied Physics and Applied Mathematics, Columbia university

  • Soham Banerjee

    • Applied Physics , University of Columbia
    • Columbia Univ
    • Brookhaven Natl Lab
    • Department of Applied Physics and Applied Mathematics, Columbia university

  • Andrew Wieteska

    • Physics, Columbia Univ
    • Department of Physics, Columbia university

  • Chris Marianetti

    • Columbia University
    • Physics, Columbia Univ
    • Department of Applied Physics and Applied Mathematics, Columbia university
    • Columbia Univ
    • Columbia

  • Benjamin Frandsen

    • Materials Sciences Division, Lawrence Berkeley National Laboratory
    • Physics, University of California, Berkeley
    • Univ of California - Berkeley
    • Department of Physics, University of California, Berkeley

  • Hubertus Luetkens

    • Paul Scherrer Institute
    • Paul Sherrer Institut
    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute

  • Zizhou Gong

    • Department of Physics, Columbia university

  • Sky Cheung

    • Department of Physics, Columbia university

  • Chris Baines

    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute

  • Alexander Shengelaya

    • Tbislisi State University
    • Department of Physics, Tbilisi State University

  • Grigol Taniashvili

    • Department of Physics, Tbilisi State University

  • Abhay Pasupathy

    • Columbia University
    • Columbia Univ
    • Physics, Columbia Univ
    • Department of Physics, Columbia university

  • Elvezio Morenzoni

    • Paul Scherrer Institute
    • Paul Sherrer Institut
    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute

  • Simon Billinge

    • Applied Physics , University of Columbia
    • Department of Applied Physics and Applied Mathematics, Columbia university

  • Alex Amato

    • Paul Scherrer Institute
    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute

  • Robert Cava

    • Department of Chemistry, Princeton University
    • Princeton
    • Princeton University
    • Chemistry, Princeton Univ
    • Princeton Univ

  • Rustem Khasanov

    • Paul Scherrer Institute
    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute
    • Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institute

  • Yasutomo Uemura

    • Columbia Univ
    • Department of Physics, Columbia University
    • Columbia University
    • Department of Physics, Columbia university