Regensburg 2022 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 23: Computational Materials Modelling: Magnetic & Electrical Properties

MM 23.7: Vortrag

Mittwoch, 7. September 2022, 17:30–17:45, H44

Modeling Temperature-Dependent Electronic Structure of Semiconductors with a Dynamic Tight-Binding Approach — •Martin Schwade, Maximilian Schilcher, and David Egger — Department of Physics, Technical University of Munich, Garching, Germany

For theoretical calculations of large-scale system sizes or longer time-scale phenomena the computational costs of typical density functional theory can present a steep barrier, which needs to be tackled by development of alternative approaches. Here, we propose an extension of the tight-binding (TB) formalism which allows for the calculation of macroscopic and temperature-dependent properties of semiconductors with little computational effort. In contrast to previous formulations, we fit TB parameters to first-principles energy eigenvalues using machine learning techniques. Furthermore, our TB approach employs hybrid orbital basis functions and addresses the problem of distance-dependent matrix elements by numerical integration of these orbitals. With this, we can maintain the average symmetry of the system as best as possible but still account for dynamic changes to that symmetry, e.g., by lattice distortions and other thermal effects. Our method is particularly helpful for getting an accurate solution of the electronic-structure problem for semiconductors at finite temperatures.