Mean-field approximation for thermodynamic and spectral functions of correlated electrons: strong coupling and arbitrary band filling

0482157 - FZÚ 2018 RIV US eng J - Journal Article
Janiš, Václav - Pokorný, Vladislav - Kauch, Anna
Mean-field approximation for thermodynamic and spectral functions of correlated electrons: strong coupling and arbitrary band filling.
Physical Review B. Roč. 95, č. 16 (2017), s. 1-12, č. článku 165113. ISSN 2469-9950. E-ISSN 2469-9969
R&D Projects: GA ČR GA15-14259S
Institutional support: RVO:68378271
Keywords : parquet equations * Hubbard model * self-consistency
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.813, year: 2017

We present a construction of a mean-field theory for thermodynamic and spectral properties of correlated electrons reliable in the strong-coupling limit. We introduce an effective interaction determined self-consistently from the reduced parquet equations. It is a static local approximation of the two-particle irreducible vertex, the kernel of a potentially singular Bethe-Salpeter equation. The effective interaction enters the Ward identity from which a thermodynamic self-energy, renormalizing the one-electron propagators, is determined. The dynamical Schwinger-Dyson equation with the thermodynamic propagators is then used to calculate the spectral properties. The thermodynamic and spectral properties of correlated electrons are in this way determined on the same footing and in a consistent manner. Such a mean-field approximation is analytically controllable and free of unphysical behavior and spurious phase transitions.

Permanent Link: http://hdl.handle.net/11104/0277552