Predominance of non-adiabatic effects in zero-point renormalization of the electronic band gap
| Autor: | Véronique Brousseau-Couture, Steven G. Louie, Xavier Gonze, Gabriel Antonius, Emile Godbout, Matteo Giantomassi, Yang-Hao Chan, Anna Miglio, Michel Côté |
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| Přispěvatelé: | UCL - SST/IMCN/MODL - Modelling |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Band gap Phonon FOS: Physical sciences Zero-point energy 02 engineering and technology 01 natural sciences Adiabatic theorem Renormalization 0103 physical sciences lcsh:TA401-492 General Materials Science 010306 general physics Adiabatic process Absolute zero lcsh:Computer software Condensed Matter - Materials Science Condensed matter physics Degenerate energy levels Materials Science (cond-mat.mtrl-sci) 021001 nanoscience & nanotechnology Computer Science Applications lcsh:QA76.75-76.765 Mechanics of Materials Modeling and Simulation lcsh:Materials of engineering and construction. Mechanics of materials 0210 nano-technology |
| Zdroj: | npj Computational Materials, vol 6, iss 1 npj Computational Materials, Vol. 6, no.1, p. 167 (2020) npj Computational Materials, Vol 6, Iss 1, Pp 1-8 (2020) |
| ISSN: | 2057-3960 |
| Popis: | Electronic and optical properties of materials are affected by atomic motion through the electron-phonon interaction: not only band gaps change with temperature, but even at absolute zero temperature, zero-point motion causes band-gap renormalization. We present a large-scale first-principles evaluation of the zero-point renormalization of band edges beyond the adiabatic approximation. For materials with light elements, the band gap renormalization is often larger than 0.3 eV, and up to 0.7 eV. This effect cannot be ignored if accurate band gaps are sought. For infrared-active materials, global agreement with available experimental data is obtained only when non-adiabatic effects are taken into account. They even dominate zero-point renormalization for many materials, as shown by a generalized Fr\"ohlich model that includes multiple phonon branches, anisotropic and degenerate electronic extrema, whose range of validity is established by comparison with first-principles results. Comment: Note that the supplementary material, included in the main file, is structured differently than in the published version, with a different numbering scheme |
| Databáze: | OpenAIRE |
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