Coherent phonon excitation in K-doped BaFe$_2$As$_2$ studied by trARPES

ORAL

Abstract

The phase diagrams of Fe-based superconductors are complex and contain magnetism, nematicity and superconductivity. To understand the emergence of superconductivity in these materials, it is crucial to study the interplay of charge, spin, orbital and lattice degrees of freedom. Here, we focus on electron-phonon coupling, which is intimately connected to the properties of the nematic phase and has been suggested to be enhanced in the presence of electronic correlations. We use time- and angle-resolved photoemission spectroscopy to study the electron-phonon coupling in K-doped BaFe$_2$As$_2$. The coherent response after optical excitation reveals at least four bosonic modes. One of them corresponds to the E$_g$-phonon mode, which is directly connected to the symmetry of the structural transition. This observation provides the opportunity to further study the interplay of electronic and lattice degrees of freedom in a nematically ordered system.

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Authors

  • Heike Pfau

    Stanford University and SLAC National Accelerator Laboratory

  • Hadas Soifer

    Stanford University and SLAC National Accelerator Laboratory

  • Jonathan Sobota

    Stanford Univ, SLAC National Accelerator Lab, Lawrence Berkeley National Lab, Stanford University, SLAC National Accelerator Laboratory, and Lawrence Berkeley National Laboratory

  • Alexandre Gauthier

    Stanford University and SLAC National Accelerator Laboratory

  • Harlyn Silverstein

    Stanford University and SLAC National Accelerator Laboratory

  • Johanna C. Palmstrom

    Stanford University and SLAC National Accelerator Laboratory, Stanford University

  • Costel Rotundu

    SIMES, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA, Stanford University and SLAC National Accelerator Laboratory

  • Ian R. Fisher

    Department of Applied Physics, Stanford University, Stanford University, Stanford Univ, Geballe Laboratory for Advanced Materials and Department of Applied Physics, Stanford University, Stanford, CA 94305, Stanford University and SLAC National Accelerator Laboratory

  • Patrick Kirchmann

    Stanford University and SLAC National Accelerator Laboratory

  • Zhi-Xun Shen

    Stanford University, Stanford University and SLAC National Accelerator Laboratory