APS Logo

Unexpected two-fold symmetric superconductivity in few-layer NbSe2

ORAL

Abstract

Transition metal dichalcogenides (TMDs) have attracted significant interest due to properties such as layer-dependent inversion symmetry, valley-contrasted Berry curvatures, and strong spin-orbit coupling (SOC). Few-layer niobium diselenide (NbSe2) exhibits Ising SOC, which helps stabilize the superconducting state and could lead to exotic properties such as topological superconductivity. Here, we report transport measurements of few-layer NbSe2 under in-plane external magnetic fields. In contrast to the three-fold symmetry of the lattice, we observe the magnetoresistance, critical field, and differential conductance measurements all exhibit a two-fold oscillation confined to the superconducting phase. We attribute the behavior to the mixing between two closely competing pairing instabilities. Our results demonstrate the unconventional character of the pairing interaction in a few-layer TMD, opening a new avenue to search for exotic superconductivity in this family of 2D materials.

arXiv:2004.02999

–

Presenters

  • Brett Heischmidt

    University of Minnesota

Authors

  • Alex Hamill

    University of Minnesota

  • Brett Heischmidt

    University of Minnesota

  • Egon Sohn

    Cornell University

  • Daniel Shaffer

    Emory University, University of Minnesota

  • Kan-Ting Tsai

    University of Minnesota

  • Xi Zhang

    University of Minnesota

  • Xiaoxiang Xi

    Nanjing University

  • Alexey Suslov

    National High Magnetic Field Laboratory

  • Helmuth Berger

    Laboratory of Physics of Complex Matter, École polytechnique fédérale de Lausanne, EPFL, Ecole Polytechnique Fédérale de Lausanne

  • Laszlo Forro

    EPFL, Ecole Polytechnique Fédérale de Lausanne

  • Fiona Burnell

    Department of Physics, University of Minnesota Twin Cities, University of Minnesota

  • Jie Shan

    Cornell University

  • Kin Fai Mak

    Cornell University

  • Rafael Fernandes

    University of Minnesota, School of Physics and Astronomy, University of Minnesota, Physics, University of Minnesota, School of Physics and Astronomy, University of Minnesota, Minneapolis, 55455 MN, School of Physics and Astronomy, University of Minnesota, Minneapolis

  • Ke Wang

    University of Minnesota

  • Vlad Pribiag

    University of Minnesota