Effects of nonlocal hybridization on valence and metal-insulator transitions in the Falicov-Kimball model

Abstract

The density matrix renormalization group and small cluster exact diagonalization calculations are used to examine effects of nonlocal hybridization on ground-state properties of the Falicov-Kimball model in one dimension. Special attention is devoted to the problem of hybridization induced insulator-metal transitions. It is shown that the picture of insulator-metal transitions found for the Falicov-Kimball model with nonlocal hybridization strongly differs from one found for the Falicov-Kimball model without hybridization (as well as with local hybridization). The effect of nonlocal hybridization is so strong that it can induce the insulator-metal transition, even in the half-filled band case where the ground states of the Falicov-Kimball model without hybridization are insulating for all finite Coulomb interactions. Outside the half-filled band case the metal-insulator transition driven by pressure is found for finite values of nonlocal hybridization.