Doping driven metal-insulator transitions and charge orderings in the extended Hubbard model

TL;DR

This study explores how doping influences phase transitions in an extended Hubbard model with local and non-local interactions, revealing complex charge orderings and metal-insulator transitions at zero temperature.

Contribution

It provides a detailed phase diagram showing the interplay of Coulomb interactions and doping, highlighting the stabilization of quarter-filled charge orderings.

Findings

Identification of phase transitions between charge-ordered insulators and metals.

Demonstration of the combined effect of local and non-local interactions in stabilizing phases.

Characterization of the stability and nature of various phases at zero temperature.

Abstract

We perform a thorough study of an extended Hubbard model featuring local and nearest-neighbor Coulomb repulsion. Using dynamical mean-field theory we investigated the zero temperature phase-diagram of this model as a function of the chemical doping. The interplay between local and non-local interaction drives a variety of phase-transitions connecting two distinct charge-ordered insulators, i.e., half-filled and quarter-filled, a charge-ordered metal and a Mott insulating phase. We characterize these transitions and the relative stability of the solutions and we show that the two interactions conspire to stabilize the quarter-filled charge ordered phase.