Quantifying Electron-Phonon Coupling in FeSe by Tracking Coherent Phonons

ORAL

Abstract

The superconductor FeSe is a good prototype for studying how correlation effects impact the electron-phonon coupling. Here, we present a new time-domain method to quantify the electron-phonon coupling strength: An optical femtosecond pump pulse excites a coherent A1g phonon; time-resolved x-ray diffraction tracks the coherent lattice motion while ultrafast photoemission monitors the related changes of the electronic bands. We combine the oscillatory responses from both experiments in a high-precision ‘coherent lock-in’ measurement of the electron-phonon coupling strength. Comparison with theory reveals a strong enhancement of the coupling strength in FeSe due to correlation effects.

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Authors

  • P.S. Kirchmann

    • SLAC National Accelerator Lab, USA

  • S. Gerber

    • Paul Scherrer Institut, Switzerland

  • S.-L. Yang

    • SLAC National Accelerator Lab, USA

  • H. Soifer

    • SLAC National Accelerator Lab, USA

  • D. Zhu

    • SLAC National Accelerator Lab, USA

  • J.A. Sobota

    • SLAC National Accelerator Lab, USA

  • S. Rebec

    • SLAC National Accelerator Lab, USA

  • J.J. Lee

    • SLAC National Accelerator Lab, USA

  • T. Jia

    • SLAC National Accelerator Lab, USA

  • B Moritz

    • SLAC National Accelerator Lab, USA

  • C. Jia

    • SLAC National Accelerator Lab, USA

  • Y. Li

    • SLAC National Accelerator Lab, USA

  • D. Leuenberger

    • SLAC National Accelerator Lab, USA

  • Y. Zhang

    • Peking University, China

  • H. Jang

    • SLAC National Accelerator Lab, USA

  • J.-S. Lee

    • SLAC National Accelerator Lab, USA

  • S. Song

    • SLAC National Accelerator Lab, USA

  • J.M. Glownia

    • SLAC National Accelerator Lab, USA

  • S. Nelson

    • SLAC National Accelerator Lab, USA

  • K.W. Kim

    • Chungbuk National University, Korea

  • Y.-D. Chuang

    • Lawrence Berkeley National Lab, USA

  • R.G. Moore

    • SLAC National Accelerator Lab, USA

  • T.P. Devereaux

    • SLAC National Accelerator Lab, USA

  • W.-S. Lee

    • SLAC National Accelerator Lab, USA

  • Z.-X. Shen

    • SLAC National Accelerator Lab, USA