Probing the Superfluid Density and the Superconducting Gaps under Pressure in 2H-NbSe<sub>2</sub>

ORAL

Abstract

We report on high-pressure (pmax = 2.1 GPa) muon spin rotation experiments probing the temperature-dependent magnetic penetration depth λ(T) in the layered superconductor 2H-NbSe2. Upon increasing the pressure, we observe a substantial increase of the superfluid density ns/m* ∼ 1/λ2, which we find to scale linearly with Tc. This linear scaling is considered a hallmark feature of unconventional superconductivity, especially in high-temperature cuprate superconductors. Our current results, along with our earlier findings on 1T'-MoTe2 [1], demonstrate that this linear relation is also an intrinsic property of the superconductivity in transition metal dichalcogenides, whereas the ratio Tc/TF is approximately a factor of 20 lower than the ratio observed in hole-doped cuprates. We, furthermore, find that the values of the superconducting gaps are insensitive to the suppression of the quasi-two-dimensional CDW state, indicating that the CDW ordering and the superconductivity in 2H-NbSe2 are independent of each other.

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

*Authors acknowledge the financial support by the Swiss National Science Foundation, US NSF DMREF and US DOE/BES grants.

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Presenters

  • Zurab Guguchia

    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute
    • Paul Scherrer Institut
    • Princeton University
    • Columbia University
    • Brookhaven National Laboratory

Authors

  • Zurab Guguchia

    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute
    • Paul Scherrer Institut
    • Princeton University
    • Columbia University
    • Brookhaven National Laboratory

  • Fabian von Rohr

    • Department of Chemistry, University of Zürich

  • Orain Jean Christophe

    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute
    • PSI, 5232 Villigen, Switzerland

  • Rustem Khasanov

    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute
    • Paul Scherrer Institut
    • Paul Scherrer Institute
    • Paul Sherrer Institut
    • PSI, 5232 Villigen, Switzerland

  • Alex Amato

    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute

  • Abhay Pasupathy

    • Columbia University
    • Physics, Columbia University
    • Department of Physics, Columbia University in the City of New York
    • Physics Department, Columbia University
    • Department of Physics, Columbia University

  • Zahid Hasan

    • Department of Physics, Princeton University
    • Princeton University
    • Laboratory for Topological Quantum Matter & Advanced Spectroscopy, Princeton University
    • Physics, Princeton U.

  • Hubertus Luetkens

    • Paul Scherrer Institute, Villigen, Switzerland
    • Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute
    • Paul Scherrer Institut

  • Yasutomo J Uemura

    • Columbia University
    • Department of Physics, Columbia University