Kosterlitz-Thouless Transition and Short Range Spatial Correlations in an Extended Hubbard Model

TL;DR

This paper investigates how intersite and local correlations influence phase transitions in a spinless two-band extended Hubbard model, revealing a transition from Fermi liquid to non-Fermi liquid states and a connection to Kosterlitz-Thouless physics.

Contribution

It introduces an analysis of the extended Hubbard model in infinite dimensions, identifying a new line of non-Fermi liquid fixed points and linking intersite correlations to phase transition behavior.

Findings

Intersite density fluctuations suppress the charge Kondo energy scale.

A Fermi liquid to non-Fermi liquid transition occurs for repulsive interactions.

In the absence of intersite interactions, the transition reduces to a Kosterlitz-Thouless transition.

Abstract

We study the competition between intersite and local correlations in a spinless two-band extended Hubbard model by taking an alternative limit of infinite dimensions. We find that the intersite density fluctuations suppress the charge Kondo energy scale and lead to a Fermi liquid to non-Fermi liquid transition for repulsive on-site density-density interactions. In the absence of intersite interactions, this transition reduces to the known Kosterlitz-Thouless transition. We show that a new line of non-Fermi liquid fixed points replace those of the zero intersite interaction problem.