Theory of the exciton-phonon coupling

ORAL

Abstract

The influence of electron-phonon interactions on optical absorption spectra requires a special treatment in materials with strong electron-hole interactions. We conceptualize these effects as exciton-phonon coupling [1]. Through phonon absorption and emission processes, the optically accessible excitons are scattered into other dark, finite-momentum exciton states. The exciton-phonon self energy therefore contributes to the temperature dependence of the optical transitions and their broadening. Two-bands model [2] shows how the full exciton-phonon self energy differs both qualitatively and quantitatively from commonly used approximations. We present the implementation of a first-principles calculation scheme, making use of density functional theory (DFT), density function perturbation theory (DFPT), and the Bethe-Salpeter equation (GW-BSE) formalism.
[1] Gabriel Antonius and Steven G. Louie. arXiv:1705.04245 [cond-mat], May 2017.
[2] Daniel Gunlycke and Frank Tseng. PCCP, 18(12):8579–8586, March 2016.

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Presenters

  • Gabriel Antonius

    Physics, Univ of California - Berkeley, Univ of California - Berkeley, University of California, Berkeley and Lawrence Berkeley National Lab, Physics, UC Berkeley, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory

Authors

  • Gabriel Antonius

    Physics, Univ of California - Berkeley, Univ of California - Berkeley, University of California, Berkeley and Lawrence Berkeley National Lab, Physics, UC Berkeley, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory

  • Steven Louie

    Physics, University of California, Berkeley, University of California, Berkeley, Physics, Univ of California - Berkeley, Univ of California - Berkeley, Physics, UC Berkeley, Physics Department, UC Berkeley and Lawrence Berkeley National Lab, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Department of Physics, University of California, Berkeley, Physics Department, University of California Berkeley and Lawrence Berkeley National Lab, Department of physics, University of California - Berkeley, Lawrence Berkeley National Lab and University of California - Berkeley, Materials Sciences Division, Lawrence Berkeley National Laboratory & Department of Physics, University of California at Berkeley, UC Berkeley and Lawrence Berkeley National Lab, Physics, University of California - Berkeley