相关论文: Mott-Peierls Transition in the extended Peierls-Hu…
In order to clarify the physics of the crossover from a Peierls band insulator to a correlated Mott-Hubbard insulator, we analyze ground-state and spectral properties of the one-dimensional half-filled Holstein-Hubbard model using…
In an attempt to clarify the nature of the crossover from a Peierls band insulator to a Mott Hubbard insulator, we analyze ground-state and spectral properties of the one-dimensional half-filled Holstein Hubbard model using exact…
We re-examine the Peierls insulator to Mott insulator transition scenario in the one-dimensional Holstein-Hubbard model where, at half-filling, electron-phonon and electron-electron interactions compete for establishing charge- and…
We report quantum Monte Carlo (stochastic series expansion) results for the transition from a Mott insulator to a dimerized Peierls insulating state in a half-filled, 1D extended Hubbard model coupled to optical bond phonons. Using…
We study the Mott transition in Hubbard models with a degenerate band on different 3-dimensional lattices. While for a non-degenerate band only the half-filled system may exhibit a Mott transition, with degeneracy there can be a transition…
We study the one-dimensional Holstein model with spin-1/2 electrons at half-filling. Ground state properties are calculated for long chains with great accuracy using the density matrix renormalization group method and extrapolated to the…
A new two-pole approximation, which allows to describe the transition from an insulating state to a metallic one at increase of bandwidth, and also the observable in some compounds transition from a metalic state to an insulating one with…
The ground state phase diagram of the half-filled repulsive Hubbard model in a bilayer is investigated using cluster dynamical mean field theory. For weak to intermediate values of Coulomb repulsion $U$, the system undergoes a transition…
We investigate the ground-state phase diagram of the one-dimensional half-filled Hubbard model with an alternating potential--a model for the charge-transfer organic materials and the ferroelectric perovskites. We numerically determine the…
We consider the dimer Hubbard model within Dynamical Mean Field Theory to study the interplay and competition between Mott and Peierls physics. We describe the various metal-insulator transition lines of the phase diagram and the break down…
The Hubbard-Holstein model is one of the simplest to incorporate both electron-electron and electron-phonon interactions. In one dimension at half filling the Holstein electron-phonon coupling promotes onsite pairs of electrons and a…
A powerful new impurity solver is shown to permit a systematic study of the doping driven Mott transition in a one-band Hubbard model within the framework of single-site dynamical mean field theory. At small dopings and large interaction…
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…
As a generic model describing quasi-one-dimensional Mott and Peierls insulators, we investigate the Holstein-Hubbard model for half-filled bands using numerical techniques. Combining Lanczos diagonalization with Chebyshev moment expansion…
We derive the disorder vs. doping phase diagram of the doped Hubbard model via Dynamical Mean Field Theory combined with Typical Medium Theory, which allows the description of both Mott (correlation driven) and Anderson (disorder driven)…
We investigate the ground-state phase diagram of the one-dimensional "ionic" Hubbard model with an alternating periodic potential at half-filling by numerical diagonalization of finite systems with the Lanczos and density matrix…
Motivated by the current interest in the understanding of the Mott insulators away from half filling, observed in many perovskite oxides, we study the Mott metal-insulator transition (MIT) in the doped Hubbard-Holstein model using the…
A Mott insulator sometimes induces unconventional superconductivity in its neighbors when doped and/or pressurized. Because the phase diagram should be strongly related to the microscopic mechanism of the superconductivity, it is important…
A detailed study of electronic phase transitions in the ionic Hubbard model at half filling is presented. Within the dynamical mean field approximation a series of transitions from the band insulator via a metallic state to a Mott-Hubbard…
We investigate the influence of an unoccupied band on the transport properties of a strongly correlated electron system. For that purpose, additional orbitals are coupled to a Hubbard model via hybridization. The filling is one electron per…