Superconducting gap in LiFeAs from three-dimensional spin-fluctuation pairing calculations

ORAL

Abstract

The lack of nesting of Fermi-surface sheets in the Fe-based superconductor LiFeAs, with a $T_c$ of 18 K, has led to questions as to whether the origin of superconductivity in this material might be different from other Fe-based superconductors. Here we present calculations of the superconducting gap and pairing in the random-phase approximation using Fermi surfaces derived from ARPES. The gaps obtained are qualitatively different from previous 2D theoretical works and in good agreement with ARPES on the main Fermi-surface pockets. We analyze the contributions to the pairing vertex thus obtained and show that the scattering processes between electron and hole pockets still dominate the pairing as in other Fe-based superconductors despite the lack of nesting, leading to gaps with anisotropic $s_\pm$ structure.

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Authors

  • Yan Wang

    HI875049, Department of Physics, University of Florida, Gainesville, FL 32611, Department of Physics, University of Florida, Gainesville, FL 32611, USA

  • Andreas Kreisel

    Department of Physics, University of Florida, Gainesville, FL 32611, Department of Physics, University of Florida, Gainesville, FL 32611, USA

  • Peter Hirschfeld

    Department of Physics, University of Florida, Gainesville, FL, Department of Physics, University of Florida, Gainesville, FL 32611, Department of Physics, University of Florida, Gainesville, FL 32611, USA, Unversity of Florida, Department of Physics, University of Florida

  • Volodymyr Zabolotnyy

    Leibniz-Institute for Solid State Research, IFW-Dresden, D-01171 Dresden, Germany

  • Sergey Borisenko

    Leibniz-Institute for Solid State Research, IFW-Dresden, D-01171 Dresden, Germany

  • Bernd B\"uchner

    Leibniz-Institute for Solid State Research, IFW-Dresden, D-01171 Dresden, Germany

  • Thomas Maier

    Center for Nanophase Materials Sciences and Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, Center for Nanophase Materials Sciences and Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6494, USA, Oak Ridge National Laboratory, ORNL

  • Douglas Scalapino

    Department of Physics, University of California, Santa Barbara, CA 93106, UCSB, Department of Physics, University of California, Santa Barbara, CA 93106-9530, USA