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.

*Work is funded by the U.S. DOE, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under Con- tract No. DE-AC02-05-CH11231 within the Quantum Materials Program (KC2202).

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