Asymmetric Hubbard model within generating functional approach in dynamical mean field theory
Ihor V. Stasyuk, O. B. Hera
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 -1 σ 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.
Condensed Matter Physics•Jan 1, 2006•3 citations