A Theoretical Study of Phase Separation in Strongly Correlated Electron Systems with Wide and Narrow Bands

Using the theoretical formalism of A. O Sboychakov6 and R. Schaffer et al.7, we have theoretically studied the phase separation in strongly correlated electron systems with wide and narrow bands. We observed the following facts; (1) In this paper, the spinless Falicov-Kimball model on the simple cubic lattice is analyzed. The analysis is performed with the help of Hubbard-I and dynamical mean field (DMFT) approximations. We have obtained the Matsubara and real frequency itinerant Green’s function, the evolution of the system with doping and the range of phase separation is evaluated in thesr two approximations. (2) We observed that at large values of the on-site Coulomb repulsion in both approximations gives similar results. It was observed that both approximations coincide in the narrow band limit W—0. (3) It was also seen that the system remains unstable towards the phase separation even at finite band width. (4) The analysis also reveals the fact that the phase separation is the inherent feature of Hubbard like models with wide and narrow bands.