Condensed Matter Physics (Jan 2006)

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

  • I.V.Stasyuk,
  • O.B.Hera

DOI
https://doi.org/10.5488/CMP.9.3.587
Journal volume & issue
Vol. 9, no. 3
pp. 587 – 602

Abstract

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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.

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