Anisotropic pairing gap in FeSe

ORAL

Abstract

Superconductivity in FeSe occurs deep inside the nematic phase, but in the absence of any form of magnetic order. As a result, FeSe provides a unique opportunity to investigate pairing in an electronic nematic state, which reconstructs the low-energy band dispersions. We solved the pairing problem within the low-energy model of FeSe, which includes the orbital content of low-energy excitations. We found deep minima of a superconducting gap on the distorted hole pocket. The location of the minima depends on two features: the relative magnitude of the intra-orbital and inter-orbital pairing interactions, and the relative sign of the nematic order parameters on hole and electron pockets. We also discuss a possibility that superconducting order evolves below Tc and breaks time-reversal symmetry below a certain T<Tc. We compare our results with recent experiments in stoichiometric FeSe and S-doped FeSe.

*The work was partly supported by the National High Magnetic Field Laboratory through NSF Grant No. DMR-1157490, the State of Florida, and U. S. DOE, Office of Science, Basic Energy Sciences, under award number de-sc0012336.

Presenters

  • Jian Kang

    • Physics, Florida State
    • National High Magnetic Field Laboratory, Florida State Univ

Authors

  • Jian Kang

    • Physics, Florida State
    • National High Magnetic Field Laboratory, Florida State Univ
  • Debanjan Chowdhury

    • MIT
    • Massachusetts Inst of Tech-MIT
    • Massachusetts Institute of Technology
    • Department of Physics, Massachusetts Institute of Technology
    • Physics, Massachusetts Inst of Tech-MIT
  • Andrey Chubukov

    • Univ of Minnesota - Twin Cities
    • Physics, University of Minnesota
    • Department of Physics, Univ of Minnesota - Twin Cities
    • Univ of Minn - Minneapolis
    • University of Minnesota
    • Physics, University of Minnesota Twin Cities
    • School of Physics & Astronomy, Univ of Minnesota - Twin Cities
    • School of Physics and Astronomy, University of Minnesota
  • Rafael Fernandes

    • School of Physics and Astronomy, University of Minnesota
    • School of Physics and Astronomy , University of Minnesota
    • School of Physics and Astronomy, Univ of Minnesota - Twin Cities
    • Univ of Minn - Minneapolis
    • School of Phys., Univ. of Minnesota - Minneapolis
    • University of Minnesota