Berlin 2024 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 2: Focus Session: Frontiers of Electronic-Structure Theory – Advances in Time-Dependent and Nonequilibrium Ab Initio Methods I

O 2.5: Vortrag

Montag, 18. März 2024, 11:30–11:45, HE 101

Electron-phonon interaction in silicon and diamond using Gaussian orbitals — •Gerrit Johannes Mann, Thorsten Deilmann, and Michael Rohlfing — Institute of Solid State Theory, University of Münster, Germany

Electron-phonon interaction is a crucial mechanism in solid state physics that is responsible for a multitude of phenomena. However, in electronic structure calculations it is often neglected. We developed an ab-initio implementation on top of density functional theory that combines finite differences calculations with the perturbative Allen-Heine-Cardona framework in order to calculate the temperature-dependent renormalization of the electronic bandstructure due to electron-phonon interaction using a basis set of localized Gaussian orbitals.
Our implementation circumvents the limiting problems of previous implementations while maintaining a good agreement with the literature. For the direct band gaps of silicon and diamond we find a zero-point renormalization of −43 meV and −411 meV, respectively. In addition, the approach allows to evaluate Debye-Waller contributions beyond the rigid-ion approximation.

Keywords: electron-phonon interaction; ab-initio calculations; zero-point renormalization; Allen-Heine-Cardona theory; Gaussian orbitals