相关论文: Strong-coupling approach to the Mott--Hubbard insu…

Near a Mott transition, strong electron correlations may enhance Cooper pairing. This is demonstrated in the Dynamical Mean Field Theory solution of a twofold-orbital degenerate Hubbard model with inverted Hund's rules on-site exchange,…

Recent investigations of the magnetic properties and the discovery of superconductivity in quasi-one-dimensional triangular lattice organic charge-transfer solids have indicated the severe limitations of the effective 1/2-filled band…

We study the Mott insulating phase of the one-dimensional Hubbard model using a local-density approximation (LDA) that is based on the Bethe Ansatz (BA). Unlike conventional functionals, the BA-LDA has an explicit derivative discontinuity.…

The half-filled Hubbard model on the Bethe lattice with coordination number $z=3$ is studied using the density-matrix renormalization group (DMRG) method. Ground-state properties such as the energy $E$, average local magnetization $<\hat…

Inspired by recent discovery of correlated insulating states in twisted bilayer graphene (TBG), we study a two-orbital Hubbard model on the honeycomb lattice with two electrons per unit cell. Based on the real-space density matrix…

We study the magnetic interactions in Mott-Hubbard systems with partially filled $t_{2g}$-levels and with strong spin-orbit coupling. The latter entangles the spin and orbital spaces, and leads to a rich variety of the low energy…

We have investigated the half-filling two-orbital Hubbard model on a triangular lattice by means of the dynamical mean-field theory (DMFT). The densities of states and optical conductivity clearly show the occurence of metal-insulating…

With the aid of both a semi-analytical and a numerically exact method we investigate the charge dynamics in the vicinity of half-filling in the one- and two-dimensional $t$-$J$ model derived from a Fermi-Hubbard model in the limit of large…

We calculate the dynamical current and kinetic-energy correlation functions for the first Mott lobe of the one-dimensional Bose-Hubbard model. We employ the strong-coupling expansion up to sixth order in $x=t/U$, and the dynamical…

Motivated by recent experiment on the Na$_4$Ir$_3$O$_8$ compound we study the Hubbard model on the "hyper-kagome lattice", which forms a three-dimensional network of corner sharing triangles, using dynamical cluster approximation (DCA)…

We study the weakly disordered Bose-Hubbard model on a cubic lattice through a one-loop renormalization group analysis of the corresponding effective field theory which is explicitly derived by combining a strong-coupling expansion with a…

Simple analytical parametrizations for the ground-state energy of the one-dimensional repulsive Hubbard model are developed. The charge-dependence of the energy is parametrized using exact results extracted from the Bethe-Ansatz. The…

We investigate the Hubbard model on a two-dimensional square lattice by the perturbation expansion to the fourth order in the on-site Coulomb repulsion U. Numerically calculating all diagrams up to the fourth order in self-energy, we…

I investigate band and Mott insulating states in a two-band Hubbard model, with the aim of understanding the differences between the idealised one-orbital model and the more realistic multi-band case. Using a projection ansatz I show that…

We extend to charge and bond operators the transformation that maps the ionic Hubbard model at half filling onto an effective spin Hamiltonian. Using these operators we calculate the amplitude of the charge density wave in different…

We investigate the Mott transition in the Kagom\'e lattice Hubbard model using a cluster extension of dynamical mean field theory. The calculation of the double occupancy, the density of states, the static and dynamical spin correlation…

The periodic Anderson model (PAM) is studied within the framework of dynamical mean-field theory, with particular emphasis on the interaction-driven Mott transition it contains, and on resultant Mott insulators of both Mott-Hubbard and…

We compute scattering rates for electrons in the two-dimensional Hubbard model for a one-orbital metal and a two-orbital band insulator by means of the Boltzmann scattering equation (BSE) and dynamical mean-field theory (DMFT). As an…

The Hubbard model, first formulated by physicist John Hubbard in the 1960s, is a simple theoretical model of interacting quantum particles in a lattice. The model is thought to capture the essential physics of high-temperature…

Using inhomogeneous dynamical mean-field theory, we argue that the normal-metal proximity effect forces any finite number of "barrier" planes that are described by the (paramagnetic) Hubbard model and sandwiched between semi-infinite…