Efficient Bethe-Salpeter equation treatment in dynamical mean-field theory

Author(s)
Agnese Tagliavini, Stefan Hummel, Nils Wentzell, Sabine Andergassen, Alessandro Toschi, Georg Rohringer
Abstract

We present here two alternative schemes designed to correct the high-frequency truncation errors in the numerical treatment of the Bethe-Salpeter equations. The schemes are applicable to all Bethe-Salpeter calculations with a local two-particle irreducible vertex, which is relevant, e.g., for the dynamical mean-field theory (DMFT) and its diagrammatic extensions. In particular, within a purely diagrammatic framework, we could extend existing algorithms for treating the static case in the particle-hole sector to more general procedures applicable to all bosonic frequencies and all channels. After illustrating the derivation and the theoretical interrelation of the two proposed schemes, these have been applied to the Bethe-Salpeter equations for the auxiliary Anderson impurity models of selected DMFT calculations, where results can be compared against a numerically "exact" solution. The successful performance of the proposed schemes suggests that their implementation can significantly improve the accuracy of DMFT calculations at the two-particle level, in particular for more realistic multiorbital calculations where the large number of degrees of freedom substantially restricts the actual frequency range for numerical calculations, as well as-on a broader perspective-of the diagrammatic extensions of DMFT.

Organisation(s)
Physics of Nanostructured Materials
External organisation(s)
Technische Universität Wien, Eberhard Karls Universität Tübingen, National University of Science and Technology (MISiS), French Atomic Energy Commission (CEA)
Journal
Physical Review B
Volume
97
No. of pages
17
ISSN
2469-9950
DOI
https://doi.org/10.1103/PhysRevB.97.235140
Publication date
06-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
Condensed matter
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/efficient-bethesalpeter-equation-treatment-in-dynamical-meanfield-theory(3e261bf1-cbd8-49cc-b8d8-8ba8927551e1).html