Regensburg 2022 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 12: Computational Materials Modelling: Physics of Ensembles 1
MM 12.3: Talk
Tuesday, September 6, 2022, 10:45–11:00, H44
Converging tetrahedron method calculations for non-dissipative parts of spectral functions — •Minsu Ghim1,2,3 and Cheol-Hwan Park1,2,3 — 1Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea — 2Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea — 3Center for Theoretical Physics, Seoul National University, Seoul 08826, Korea
Integrations in k space are used to calculate many of the physical quantities in solid-state physics. Examples include various static or dynamical conductivity, self-energy of an electron, and electric polarizability. The integral usually takes the form of a product of proper matrix elements and 1/[ℏω − (єmk − єnk) + iη], which is decomposed into the real part and the imaginary part, P{ 1/[ℏω − (єmk − єnk)]} and −iπδ [ℏω − (єmk − єnk)], respectively. Here, ω is the frequency, єmk and єnk are the energies of the valence and conduction electronic bands with Bloch wavevector k, respectively, and η = 0+. Although the delta-function part has been widely calculated by the tetrahedron method, the non-dissipative principal value integral part has not. Tools to obtain matrix elements and energy eigenvalues from first principles have been actively developed, but there are technical difficulties in the tetrahedron method for the non-dissipative part. In this talk, we introduce an easy-to-implement, stable method to overcome those obstacles. Furthermore, our method is tested by calculating the spin Hall conductivity of fcc platinum.