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Short-range nematic fluctuations in Sr1-xNaxFe2As2

POSTER

Abstract


Abundant evidence indicates that nematic fluctuations are closely related to unconventional superconductivity. For both hole- and electron-doped iron-based superconductors (FeSCs), the underdoped phase space is widely inhabited by intertwined nematic and magnetic orders. Hole-doped FeSCs, such as Sr1-xNaxFe2As2, uniquely exhibit a re-entrant tetragonal magnetic (AFM-T) phase before entering the superconducting phase in the underdoped (UD) regime. By using inelastic x-ray scattering, we observed softened transverse acoustic phonons in the UD sample that harbors the AFM-T phase, and the optimal-doped (OP) sample. By extracting both the nematic susceptibility and correlation length, we find a large nematic susceptibility persisting in the AFM-T phase, and a short nematic correlation length ξ ~ 10 Å that is much smaller than that on the electron-doped side. The OP sample manifests weaker phonon softening effect, indicative of reduced fluctuations. This result indicates that short-range nematic fluctuations may be an important ingredient favorable for superconductivity.

Presenters

  • Shan Wu

    Lawrence Berkeley National Laboratory

Authors

  • Shan Wu

    Lawrence Berkeley National Laboratory

  • Yu Song

    Zhejiang University, Physics, University of California, Berkeley

  • Yu He

    Applied Physics, Yale University, Yale University, Physics, University of California, Berkeley, Stanford Univ

  • Alex Frano

    University of California, San Diego, University of California San Diego, Department of Physics, University of California, San Diego

  • Ming Yi

    Rice University, Rice Univ, Department of Physics and Astronomy, Rice University, Department of Physics and Astronomy, Rice Univ, Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice Univ

  • Xiang Chen

    Lawrence Berkeley National Laboratory

  • Hiroshi Uchiyama

    Japan Synchrotron Radiation Research Institute

  • Ahmet Alatas

    Advanced Photon Source, Argonne National Laboratory, Argonne National Laboratory, APS, Argonne National Laboratory

  • Ayman Said

    Advanced Photon Source, Argonne National Laboratory, Argonne National Laboratory, APS, Argonne National Laboratory

  • Liran Wang

    Karlsruhe Institute of Technology

  • Thomas Wang

    Karlsruhe Institute of Technology, Institut fur Festkorperphysik, Karlsruhe Institut fur Technologie

  • Christoph Meingast

    Karlsruhe Institute of Technology, IQMT, Karlsruhe Institute of Technology

  • Robert J Birgeneau

    Lawrence Berkeley National Laboratory, Physics, University of California, Berkeley, University of California, Berkeley, Department of Physics, University of California Berkeley, Department of Physics, University of California, Berkeley