Efficient Bethe-Salpeter equation treatment in dynamical mean-field theory
| Autor: | Alessandro Toschi, Nils Wentzell, G. Rohringer, Agnese Tagliavini, Stefan Hummel, Sabine Andergassen |
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| Rok vydání: | 2018 |
| Předmět: |
Bethe–Salpeter equation
Strongly Correlated Electrons (cond-mat.str-el) Degrees of freedom (statistics) FOS: Physical sciences 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Vertex (geometry) Condensed Matter - Strongly Correlated Electrons Range (mathematics) Diagrammatic reasoning Dynamical mean field theory 0103 physical sciences Condensed Matter::Strongly Correlated Electrons Statistical physics 010306 general physics 0210 nano-technology Mathematics |
| Zdroj: | Physical Review B. 97 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.97.235140 |
| Popis: | 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 local, 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 dynamical mean-field theory (DMFT) calculations at the two-particle level, in particular for more realistic multi-orbital 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. 20 pages, 12 figures |
| Databáze: | OpenAIRE |
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