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

Li Huang (1) , Thomas Ayral (2, 3) , Silke Biermann (3, 4) , Philipp Werner (1)

1 University of Fribourg
2 IPHT - Institut de Physique Théorique - UMR CNRS 3681
3 CPHT - Centre de Physique Théorique [Palaiseau]
4 Collège de France - Chaire Physique de la matière condensée (A. Georges)

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.

Domains: Physics [physics]

Li Huang, Thomas Ayral, Silke Biermann, Philipp Werner. Extended dynamical mean-field study of the Hubbard model with long range interactions. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2014, 90 (19), pp.5114. ⟨10.1103/PhysRevB.90.195114⟩. ⟨cea-01342149⟩