Regensburg 2022 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 33: Optical Properties 2
HL 33.1: Vortrag
Donnerstag, 8. September 2022, 15:00–15:15, H32
Implementation of the Bethe-Salpeter Equation using Crystal Symmetries — •Jörn Stöhler1,2, Dmitrii Nabok1, Stefan Blügel1, and Christoph Friedrich1 — 1Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich, Germany — 2RWTH Aachen University, Germany
The Bethe-Salpeter equation (BSE) and GW approximation are two many-body perturbation theory techniques that together form the state-of-the-art method to include electron-hole interaction in periodic systems. The BSE has proven to be the most accurate tool to compute optical absorption for the valence and core energy region, as well as electron energy loss.
We have implemented the BSE in the SPEX code, a full-potential linearized augmented planewave (FLAPW) code that supports Green-function based methods including the GW approximation, optical spectra in the random phase approximation, and more. We use crystal symmetries to achieve a significant computational speedup for the construction and diagonalization of an effective electron-hole Hamiltonian in the Tamm-Dancoff approximation, from which we obtain symmetric exciton wavefunctions and energies.
Our code is parallelized and has been tested for various bulk, layered and monolayer semiconductors, among them LiF and MoS2, and includes spin-orbit coupling. The results agree with available theoretical and experimental spectra from the literature.