Phase separation in the strongly correlated Falicov-Kimball model in infinite dimensions

Abstract

Phase separation in the strongly correlated Falicov-Kimball model in infinite dimensions is examined. We show that the phase separation can occur for any values of the interaction constant J ^* when the site energy ε ⁰ of the localized electrons is equal to zero. Electron-poor regions always have homogeneous state and electron-rich regions have chessboard state for J ⁰ ≥ 0.03, chessboard state or homogeneous state in dependence upon temperature for 0 < J ^* < 0.03 and homogeneous state for J ^* = 0. For J ^* = 0 and T = 0, phase separation (segregation) occurs at −1 < ε ⁰ < 0. The obtained results are exact for the Bethe lattice with infinite number of the nearest neighbours.