Phonon linewidth due to electron-phonon interactions with strong forward scattering in FeSe thin films on oxide substrates

ORAL

Abstract

The discovery of an enhanced superconducting transition temperature Tc in monolayers of FeSe grown on several oxide substrates has opened a different route to high-Tc superconductivity through interface engineering. One proposal for the origin of the observed enhancement is an electron-phonon interaction across the interface that is peaked at small momentum transfers. Here, we examine the implications of such a coupling on the phononic properties of the system. We find that while a strong forward scattering leads to a sizable broadening of phonon lineshape, which may result in charge instabilities at long-wavelengths, the inclusion of Coulombic screening significantly reduces the phonon broadening, thus explaining the lack of anomalously broad phonon linewidths in the FeSe interface systems as shown by experiments. We also show in what parameter range and conditions, the Tc enhancement and the replica band feature in the electron spectral function can persist with the screened electron-phonon coupling in the forward scattering direction.

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Presenters

  • Yan Wang

    Physics, University of Sherbrooke, Université de Sherbrooke, Physics, Université de Sherbrooke

Authors

  • Yan Wang

    Physics, University of Sherbrooke, Université de Sherbrooke, Physics, Université de Sherbrooke

  • Louk Rademaker

    Perimeter Institute for Theoretical Physics, Kavli Institute for Theoretical Physics, University of California Santa Barbara

  • 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

  • Steven Johnston

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