Extended dynamical mean-field study of the Hubbard model with long range interactions

TL;DR

This study uses extended dynamical mean-field theory combined with the GW approximation to analyze how long-range interactions influence phase boundaries and spectral properties in the extended Hubbard model on square and cubic lattices.

Contribution

It provides a detailed phase diagram and spectral analysis considering long-range interactions up to third nearest neighbors, highlighting their significant effects.

Findings

Long-range interactions shift phase boundaries between metallic, charge-ordered, and Mott insulating phases.

Long-range interactions modify screening modes and local spectral functions.

Momentum-dependent self-energy enhances correlation effects, competing with screening from long-range Coulomb interactions.

Abstract

Using extended dynamical mean-field theory and its combination with the $GW$ approximation, we compute the phase diagrams and local spectral functions of the single-band extended Hubbard model on the square and simple cubic lattices, considering long range interactions up to the third nearest neighbors. The longer range interactions shift the boundaries between the metallic, charge-ordered insulating and Mott insulating phases, and lead to characteristic changes in the screening modes and local spectral functions. Momentum-dependent self-energy contributions enhance the correlation effects and thus compete with the additional screening effect from longer range Coulomb interactions. Our results suggest that the influence of longer range intersite interactions is significant, and that these effects deserve attention in realistic studies of correlated materials.