Dynamical Cluster Approximation Study of Electron Localization in the Extended Hubbard Model

TL;DR

This study uses the dynamical cluster approximation to analyze how electron localization and phase transitions occur in the extended Hubbard model, focusing on charge order, Mott physics, and Coulomb interactions.

Contribution

It provides new insights into the effects of nearest-neighbor Coulomb interaction on phase boundaries and electron correlations in the extended Hubbard model.

Findings

Nearest-neighbor Coulomb interaction shifts phase boundaries to larger U values.

V influences correlations differently in metallic and insulating regimes.

Charge order and Mott states exhibit distinct correlation characteristics.

Abstract

We perform a detailed study of the phase transitions and mechanisms of electron localization in the extended Hubbard model using the dynamical cluster approximation on a $2\times 2$ cluster. We explore the interplay of charge order and Mott physics. We find that a nearest-neighbor Coulomb interaction $V$ causes "screening" effects close to the Mott phase transition, pushing the phase boundary to larger values of $U$. We also demonstrate the different effects of $V$ on correlations in metallic and insulating regimes and document the different correlation aspects of charge order and Mott states.