Segregation and charge-density-wave order in the spinless Falicov-Kimball model

TL;DR

This paper provides an exact solution of the spinless Falicov-Kimball model in infinite dimensions, revealing a complex phase diagram with segregation and charge-density-wave order, and analyzing the transition behavior at various interaction strengths.

Contribution

It offers a detailed analysis of the phase competition and nonanalytic transition behavior in the model, which was not previously fully understood.

Findings

Rich phase diagram with segregation and charge-density-wave phases

Nonanalytic behavior in transition temperature at large U

Correlation-induced gap in the density of states

Abstract

The spinless Falicov-Kimball model is solved exactly in the limit of infinite-dimensions on both the hypercubic and Bethe lattices. The competition between segregation, which is present for large U, and charge-density-wave order, which is prevalent at moderate U, is examined in detail. We find a rich phase diagram which displays both of these phases. The model also shows nonanalytic behavior in the charge-density-wave transition temperature when U is large enough to generate a correlation-induced gap in the single-particle density of states.