Magnetic and pairing tendencies in quasi 1D multi-orbital BaFe2S3 ladders and chains

ORAL

Abstract

The discovery of superconductivity in the two-leg ladder compound BaFe2S3 opened a novel avenue of research because it represents the first report of pairing in a quasi-one-dimensional iron-based superconductor. Ladders and chains can be far more accurately studied using many-body techniques and model Hamiltonians than their layered counterparts. As a first step, we studied a two-orbital Hubbard model, derived from first principles, that describes individual BaFe2S3 ladders using the density matrix renormalization technique. We found indications of pairing between two holes in a region with orbital selective Mott phase characteristics [1]. By studying a simplified model on large systems, the two-orbital chain, we uncovered an instability toward pairing that is enhanced with increasing Hund and antiferromagnetic Heisenberg couplings. The analysis of the chain pair-pair correlations indicate that pairs form inter-orbital singlets on neighboring sites and different orbitals [2]. These results suggest that magnetic fluctuations may explain superconductivity in the iron-based ladder superconductors. Future directions of research in ladders and chains will be discussed.

[1] N. D. Patel et al., Phys. Rev. B 94, 075119 (2016)
[2] N. D. Patel et al., Phys. Rev. B 96, 024520 (2017)

–

Presenters

  • Nirav Patel

    Univ. of Tennessee, Physics and Astronomy, University of Tennessee

Authors

  • Nirav Patel

    Univ. of Tennessee, Physics and Astronomy, University of Tennessee

  • Alberto Nocera

    Univ. of Tennessee, Physics and Astronomy, University of Tennessee, Department of Physics and Astronomy, Univ of Tennessee, Knoxville, University of Tennessee

  • Gonzalo Alvarez

    Oak Ridge National Laboratory, Oak Ridge National Lab, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory

  • Ryotaro Arita

    RIKEN, RIKEN Center for Emergent Matter Science, CEMS, RIKEN, Center for Emergent Matter Science, RIKEN

  • Adriana Moreo

    Univ. of Tennessee, Department of Physics and Astronomy, Univ of Tennessee, Knoxville, Univ of Tennessee and ORNL., University of Tennessee, Univ of Tennessee, Knoxville, Department of Physics and Astronomy, University of Tennessee, Knoxville

  • Elbio Dagotto

    Univ. of Tennessee, Physics and Astronomy, University of Tennessee, Department of Physics and Astronomy, Univ of Tennessee, Knoxville, Department of Physics and Astronomy, University of Tennessee, University of Tennessee, University of Tennessee & Oak Ridge National Laboratory, Department of Physics and Astronomy, University of Tennessee, Knoxville