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

Beyond extended dynamical mean-field theory: Dual boson approach to the two-dimensional extended Hubbard model

Dynamical mean field solution of the Bose-Hubbard model.

We present the effective action and self-consistency equations for the bosonic dynamical mean field approximation to the bosonic Hubbard model and show that it provides remarkably accurate phase diagrams and correlation functions. To solve the bosonic dynamical mean field equations, we use a continuous-time Monte Carlo method for bosonic impurity models based on a diagrammatic expansion in the ...

Symmetries and mean-field phases of the extended Hubbard model.

The two-dimensional extended Hubbard model that includes a nearestneighbor Heisenberg interaction is studied using a mean-field theory where quasiparticles are defined by an U(8) group of canonical transformations. The theory is a generalization of the ordinary BCS theory, and Balian and Werthamer’s theory of 3He that permits both broken gauge, spin and sublattice symmetry. This allows us to in...

Cellular dynamical mean-field theory for the one-dimensional extended Hubbard model

We explore the use of exact diagonalization methods for solving the self-consistent equations of the cellular dynamical mean field theory for the one-dimensional regular and extended Hubbard models. We investigate the nature of the Mott transition and convergence of the method as a function of cluster size as well as the optimal allocation of computational resources between bath and ‘‘cluster-i...

Itinerant ferromagnetism in the multiorbital Hubbard model: a dynamical mean-field study.

In order to resolve the long-standing issue of how itinerant ferromagnetism is affected by lattice structure and Hund's coupling, we compare various three-dimensional lattice structures in the single- and multiorbital Hubbard models with the dynamical mean-field theory with an improved quantum Monte Carlo algorithm that preserves the spin-SU(2) symmetry. The result indicates that both the latti...