The influence of correlated hopping on valence and metal-insulator transitions in the Falicov-Kimball model

TL;DR

This paper investigates how correlated hopping significantly alters the phase diagram and transition behavior in the one-dimensional Falicov-Kimball model, including inducing insulator-metal transitions at half-filling.

Contribution

It demonstrates that correlated hopping drastically changes the ground-state phase diagram and transition mechanisms in the model, a novel insight compared to the conventional model.

Findings

Correlated hopping modifies the phase diagram.

It can induce insulator-metal transitions at half-filling.

The effects are strong enough to alter known transition behaviors.

Abstract

The extrapolation of small-cluster exact-diagonalization calculations is used to examine the influence of correlated hopping on valence and metal-insulator transitions in the one-dimensional Falicov-Kimball model. It is shown that the ground-state phase diagram as well as the picture of valence and metal-insulator transitions found for the conventional Falicov-Kimball model (without correlated hopping) are strongly changed when the correlated hopping term is added. The effect of correlated hopping is so strong that it can induce the insulator-metal transition, even in the half-filled band case.