Observation of Topological Surface State in High Temperature Superconductor MgB2

Invited

Abstract

Most topological superconductors known-to-date suffer from low transition temperatures (Tc) and/or high fragility to disorder and dopant levels, which greatly hamper the progress in this promising field. In this work, we suggest BCS superconductor MgB2 as a superior candidate: not only is its superconducting Tc=39K nearly triple the current record of all candidate topological superconductors, but it also has topological Dirac nodal line states which are highly tolerant against disorder and inadvertent doping variations. Our density functional theory (DFT) calculation and Angle-resolved Photoemission Spectroscopy (ARPES) measurements locate the topological Dirac Nodal Lines and their corresponding topological surface states on the [010] faces of MgB2, which could host topological superconductivity via the proximity effect to the bulk.

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Presenters

  • Xiaoqing Zhou

    University of Colorado, Boulder

Authors

  • Xiaoqing Zhou

    University of Colorado, Boulder

  • Kyle Gordon

    University of Colorado, Boulder

  • Kyung-Hwan Jin

    Physics, University of Utah, Department of Materials Science and Engineering, University of Utah, University of Utah

  • Haoxiang Li

    University of Colorado, Boulder

  • Dushyant M Narayan

    University of Colorado, Boulder

  • Hengdi Zhao

    Department of Physics, University of Colorado, Boulder CO 80309, Department of Physics, University of Colorado, Boulder, CO 80309, Department of Physics, University of Colorado at Boulder, University of Colorado, Boulder

  • Hao Zheng

    Department of Physics, University of Colorado, Boulder CO 80309, Department of Physics, University of Colorado, Boulder, CO 80309, Department of Physics, University of Colorado at Boulder, University of Colorado, Boulder

  • Huaqing Huang

    Department of Materials Science and Engineering, University of Utah, University of Utah, Physics, University of Utah

  • Gang Cao

    Department of Physics, University of Colorado-Boulder, Department of Physics, University of Colorado, Boulder CO 80309, Department of Physics, University of Colorado, Boulder, CO 80309, Department of Physics, University of Colorado at Boulder, Physics and Astronomy, University of Kentucky, University of Colorado, Boulder, University of Colorado Boulder

  • Nikolai D Zhigadlo

    University of Bern

  • Feng Liu

    Physics, University of Utah

  • Daniel Dessau

    University of Colorado, Boulder