Room temperature local nematicity in FeSe superconductor

ORAL

Abstract

We report pair distribution function measurements of the iron-based superconductor FeSe above and below the structural transition temperature. Structural analysis reveals a local orthorhombic distortion with a correlation length of about 4 nm at temperatures where an average tetragonal symmetry is observed. The analysis further demonstrates that the local distortion is larger than the global distortion at temperatures where the average observed symmetry is orthorhombic. Our results suggest that the low-temperature macroscopic nematic state in FeSe forms from an imperfect ordering of orbital-degeneracy-lifted nematic fluctuations which persist up to at least 300 K.

*This work was supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (DOE-BES) under contract No. DE-SC0012704. X-ray PDF measurements were conducted on beamline 28-ID-1 of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704.

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Presenters

  • Robert Koch

    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory

Authors

  • Robert Koch

    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory

  • Tatiana Konstantinova

    • Department of Physics and Astronomy, Stony Brook University

  • Milinda Abeykoon

    • Brookhaven National Laboratory
    • Brokhaven National Laboratory
    • Photon Science Division, Brookhaven National Laboratory

  • Aifeng Wang

    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory

  • Cedomir Petrovic

    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory
    • Brookhaven National Laboratory, NY 11973, USA

  • Yimei Zhu

    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Brookhaven National Laboratory
    • Brookhaven National Lab
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Department of Energy Science and Technology, Brookhaven National Laboratory

  • Emil Bozin

    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory

  • Simon J L Billinge

    • Brookhaven National Laboratory
    • Columbia University, Department of Applied Physics and Applied Mathematics
    • Department of Applied Physics and Applied Mathematics, Columbia University