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.

*This research was supported by the National Science Foundation under grant DMR-1508412, and by the C2SEPEM funded by the U. S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-05CH11231 at Lawrence Berkeley National Laboratory.

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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