Strong-coupling corrections to zero-point renormalization of quasiparticle band gaps

ORAL

Abstract

We investigate the question on the phonon renormalization of quasiparticle band gaps by extending the Allen-Heine theory to the case of strong electron-phonon coupling. In this regime, electron self-localization and polaron formation can provide a sizable contribution to the band gap and cannot be neglected. We perform calculations of quasiparticle band gaps in alkali halides and alkaline-earth oxides by including GW, Fan-Migdal, Debye-Waller, and polaron self-energies on the same footing. We find that the inclusion of polaronic effects improves the agreement between calculations and experiments for the zero-point renormalization of the band gap.

*This research is supported by the Computational Materials Science program of the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award DE-SC0020129. Computational resources were provided by the National Energy Research Scientific Computing Center (a DOE Office of Science User Facility supported under Contract No. DE-AC02-05CH11231), the Argonne Leadership Computing Facility (a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357), and the Texas Advanced Computing Center (TACC) at The University of Texas at Austin.

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Presenters

  • Donghwan Kim

    • University of Texas at Austin

Authors

  • Donghwan Kim

    • University of Texas at Austin

  • Jon Lafuente-Bartolome

    • University of Texas at Austin

  • Sabyasachi Tiwari

    • University of Texas at Austin

  • Tae Yun Kim

    • University of Texas at Austin

  • Zhenbang Dai

    • University of Texas at Austin

  • Chao Lian

    • University of Texas at Austin

  • Feliciano Giustino

    • University of Texas at Austin