Related papers: First- and Second Order Phase Transitions in the H…
We study two-component fermions in optical lattices with spatially alternating on-site interactions using dynamical mean-field theory. Calculating the quasi-particle weight, double occupancy, and order parameters for each sublattice, we…
We study transport properties of the half-filled two-dimensional (2D) Hubbard model with spatially varying interactions, where a pattern of interacting and non-interacting sites is formed. We use Determinantal Quantum Monte Carlo method to…
Phase diagram of the Hubbard-Holstein model in the coexistence of electron-electron and electron-phonon interactions has been theoretically obtained with the density-matrix renormalization group method for one-dimensional (1D) systems,…
We investigate nonmagnetic metal-insulator transition in the 1/5-depleted square lattice Hubbard model at half-filling within the 8-site cellular dynamical mean field theory. We find that a metal-insulator transition without any signatures…
Elucidating the physics of the single-orbital Hubbard model in its intermediate coupling regime is a key missing ingredient to our understanding of metal-insulator transitions in real materials. Using recent non-perturbative many-body…
The metal-insulator transition in VO2 was investigated using the three-band Hubbard model, in which the degeneracy of the 3d orbitals, the on-site Coulomb and exchange interactions, and the effects of lattice distortion were considered. A…
While the Hubbard model is the standard model to study Mott metal-insulator transitions, it is still unclear to which extent it can describe metal-insulator transitions in real solids, where non-local Coulomb interactions are always…
We study the Hubbard-Holstein model using slave-boson mean-field and a variation al Lang-Firsov transformation. We identify weak and strong e-ph coupling solutions, whose stability depends both on the bare e-ph coupling and on the…
Strong correlation effects, which are often associated to the approach to a Mott insulating state, in some cases may be observed even far from half-filling. This typically happens whenever the inter-site Coulomb repulsion induces a tendency…
We investigate the paramagnetic-metal-to-antiferromagnetic-metal and antiferromagnetic-metal-to- antiferromagnetic-insulator transitions using a slave-boson mean-field theory. To this effect, we discuss the ground state of the half-filled…
The two-dimensional Holstein-Hubbard model is studied by means of continuous-time quantum Monte Carlo simulations. Using renormalization-group-invariant correlation ratios and finite-size extrapolation, the critical temperature of the…
At the Mott transition, electron-electron interaction changes a metal, in which electrons are itinerant, to an insulator, in which electrons are localized. This phenomenon is central to quantum materials. Here we contribute to its…
Looking for superconductors with higher transition temperature requires a guiding principle. In conventional superconductors, electrons pair up into Cooper pairs via the retarded attraction mediated by electron-phonon coupling.…
The Hubbard-Holstein model is studied including double-exchange interaction and superexchange interaction using a variational phonon basis obtained through the modified Lang-Firsov (MLF) transformation followed by the squeezing…
We theoretically propose the occurrence of a quantum spin Hall (QSH) and a second order topological phase transition (TPT) driven by electron-phonon (e-p) coupling in a pseudospin-$1$ fermionic system on an $\alpha$-$T_3$ lattice. Our model…
We study the Holstein-Double Exchange model in three dimensions in the presence of substitutional disorder. Using a new Monte Carlo technique we establish the phase diagram of the clean model and then focus on the effect of varying…
Most nonperturbative numerical studies of electron-phonon interactions focus on model Hamiltonians where the electrons interact with a phonon branch via a single type of microscopic mechanism. Two commonly explored couplings in this context…
We investigate the metal-insulator Mott transition in a generalized version of the periodic Anderson model, in which a band of itinerant electrons is hybridrized with a narrow and strongly correlated band. Using dynamical mean-field theory,…
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 the present paper metal-insulator transition is studied in a generalized Hubbard model with correlated hopping at half-filling and zero temperature. Single-particle Green function and energy spectrum of electron system are calculated.…