Asymmetric Hubbard model within generating functional approach in dynamical mean field theory

• Date: 2006
• Main Authors: Stasyuk, I.V., Hera, O.B.
• Format: Article
• Language: English
• Published: Інститут фізики конденсованих систем НАН України 2006
• Series: Condensed Matter Physics
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/121365
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Asymmetric Hubbard model within generating functional approach in dynamical mean field theory / I.V. Stasyuk, O.B. Hera // Condensed Matter Physics. — 2006. — Т. 9, № 3(47). — С. 587–602. — Бібліогр.: 40 назв. — англ.

In the paper a new analytic approach to the solution of the effective single-site problem in the dynamical mean field theory is developed. The approach is based on the method of the Kadanoff-Baym generating functional in the form developed by Izyumov et al. It makes it possible to obtain a closed equation in functional derivatives for the irreducible part of the single-site particle Green’s function; the solution is constructed iteratively. As an application of the proposed approach the asymmetric Hubbard model (AHM) is considered. The inverse irreducible part Ξ⁻¹σ of the single-site Green’s function is constructed in the linear approximation with respect to the coherent potential Jσ. Basing on the obtained result, the Green’s function of itinerant particles in the Falicov-Kimball limit of AHM is considered, and the decoupling schemes in the equations of motion approach (GH3 approximation, decoupling by Jeschke and Kotliar) are analysed.