Electron-phonon coupling in photoexcited Bi2Te3

ORAL

Abstract



Bi2Te3 is a topological insulator and thermoelectric material with a high figure-of-merit at room temperature. Strong spin-orbit coupling leads to the inversion of its bulk valence and conduction bands, which results in the formation of topologically-protected surface states [1]. Despite this protection, the surface states may be scattered by lattice vibrations [2]. Here we study the electron-phonon interaction of the surface states in Bi2Te3 using density functional theory and density functional perturbation theory. We calculate the deformation potentials of the surface states due to coupling to the coherent A1g modes driven by photoexcitation. Our computed deformation potential values agree well with those obtained from time-resolved ARPES measurements and time-resolved Bragg diffraction. Our calculations also quantitatively reproduce the experimentally observed magnitude of the surface phonon softening. These findings open opportunities for reliable first principles predictions of the topological transport properties of Bi2Te3 and related V2-VI3 materials.

[1] Y. L. Chen et al, Nature 325, 178 (2009)
[2] K. Shrestha et al, Phys. Rev. B 95, 195113 (2017)

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Presenters

  • Jose Querales-Flores

    Tyndall National Institute, Materials Theory, Tyndall National Institute

Authors

  • Jose Querales-Flores

    Tyndall National Institute, Materials Theory, Tyndall National Institute

  • Ivana Savic

    Tyndall National Institute, Tyndall National Institute, Cork, Ireland, Materials Theory, Tyndall National Institute

  • Éamonn Murray

    Imperial College London, UK, Department of Physics and Department of Materials, Imperial College London, Department of Materials and Department of Physics, Imperial College London

  • Stephen B Fahy

    University College Cork, University College Cork, Ireland, Department of Physics, University College Cork, Department of Physics, University College Cork, Cork, Ireland, Materials Theory, Tyndall National Institute

  • Jonathan Sobota

    Stanford University, Department of Applied Physics, Stanford University, SLAC National Accelerator Laboratory

  • Samuel W Teitelbaum

    Department of Chemistry, Massachusetts Institute of Technology, SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences

  • Takahiro Sato

    Stanford PULSE Institute, SLAC National Accelerator Laboratory

  • Matthieu Chollet

    Stanford PULSE Institute, SLAC National Accelerator Laboratory

  • James M Glownia

    SLAC National Accelerator Laboratory

  • Mariano Trigo

    SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences

  • Trevor P Bailey

    Department of Physics, University of Michigan

  • Ctirad Uher

    Department of Physics, University of Michigan

  • Patrick S Kirchmann

    SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory

  • Zhi-Xun Shen

    Stanford University, SLAC National Accelerator Laboratory

  • Costel R. Rotundu

    Department of Applied Physics, Stanford University, Stanford University

  • Thomas Henighan

    Stanford University

  • David A Reis

    Stanford University