Electronic Structure and doping dependence of the electron nematic series Sr<sub>x</sub>Ba<sub>1-x</sub>Ni<sub>2</sub>As<sub>2</sub>

ORAL

Abstract

The interplay between competing ordered states and superconductivity has long been identified as key to understanding high-temperature superconductivity. In the case of the iron pnictide superconductors, superconductivity coexists with SDW order and electronic nematicity. BaNi2As2, a structural analogue of the high temperature pnictide superconductor BaFe2As2 has recently been reported to host CDW order and electronic nematicity in conjunction with superconductivity. Interestingly, as a function of Sr doping, CDW and nematicity in the system is suppressed. Upon suppression of this order to absolute zero, a dramatic, six-fold enhancement of the superconducting transition temperature is observed. This system could thus serve as a model system to study the enhancement of superconductivity in the vicinity of quantum critical fluctuations. Here we present detailed high-resolution ARPES measurements of the SrxBa1-xNi2As2 series as a function of temperature, comparing the measured band dispersion and Fermi surfaces to density functional theory calculations of the electronic structure carried out in different phases. Utilizing both the experimental and theoretical data, we discuss various mechanisms for the CDW and electronic nematicity.

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Presenters

  • Dushyant Narayan

    • University of Colorado, Boulder

Authors

  • Dushyant Narayan

    • University of Colorado, Boulder

  • PEIPEI HAO

    • University of Colorado, Boulder

  • Kyle Gordon

    • University of Colorado, Boulder

  • Andrew Linn

    • University of Colorado, Boulder

  • Haoxiang Li

    • Physics, University of Colorado Boulder
    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory

  • Bryan Berggren

    • University of Colorado, Boulder

  • Hope Whitelock

    • University of Colorado, Boulder

  • Chris Eckberg

    • Quantum Materials Center, University of Maryland, College Park
    • University of Maryland, College Park

  • Prathum Saraf

    • Quantum Materials Center, Department of Physics, University of Maryland College Park
    • Quantum Materials Center, University of Maryland, College Park
    • University of Maryland, College Park

  • John Collini

    • Quantum Materials Center, Department of Physics, University of Maryland College Park
    • University of Maryland, College Park
    • Maryland Quantum Materials Center and Department of Physics, University of Maryland, College Park

  • Johnpierre Paglione

    • University of Maryland, College Park
    • Maryland Quantum Materials Center, Department of Physics, University of Maryland
    • Quantum Materials Center, Department of Physics, University of Maryland College Park
    • Quantum Materials Center, University of Maryland, College Park
    • Maryland Quantum Materials Center and Department of Physics, University of Maryland, College Park
    • University of Maryland

  • Daniel Dessau

    • University of Colorado, Boulder
    • Physics, University of Colorado Boulder