Related papers: Large Phase Separation and Superconductivity in th…
We study a two-dimensional superconductor in close proximity to a two-dimensional metallic sheet. The electrons in the superconducting sheet are coupled to those in the metallic sheet by the Coulomb interaction only. We obtain an effective…
We study the electronic states of the anisotropic triangular lattice Hubbard model at half filling, which is a simple effective model for the organic superconducting $\kappa$-BEDT-TTF compounds. We treat the effect of the Coulomb…
We study the frequency and space dependence of the local tunneling density of states of a Luttinger liquid (LL) which is connected to a superconductor. This coupling {\em strongly} modifies the single-particle properties of the LL. It…
We study various realizations of collective coordinates, e.g. the position of a particle, the charge of a Coulomb box or the phase of a Bose or a superconducting condensate, coupled to Luttinger liquids (LL) with N flavors. We find that for…
Numerical and analytical studies of several models of correlated electrons are discussed. Based on exact diagonalization and variational Monte Carlo techniques, we have found strong indications that the two dimensional t-J model…
The two-band Hubbard model is used to analyze a possibility of a non-uniform charge distribution in a strongly correlated electron system with two types of charge carriers. It is demonstrated that in the limit of strong on-site Coulomb…
We investigate the one-dimensional(1D) d-p model, simulating a Cu-O linear chain with strong Coulomb repulsion, by using the numerical diagonalization method. Using the Luttinger liquid theory, we obtained phase diagrams of the ground state…
Universal scaling laws can guide the understanding of new phenomena, and for cuprate high-temperature superconductivity such an early influential relation showed that the critical temperature of superconductivity ($T_c$) correlates with the…
Recent computational studies of models for manganese oxides have revealed a rich phase diagram, not anticipated in early calculations in this context performed in the 1950's and 60's. In particular, the transition between the…
We show that the main features of the cuprates superconductors phase diagram can be derived considering the disorder as a key property of these materials. Our basic point is that the high pseudogap line is an onset of phase separation which…
We consider the case of a density-driven metal-superconductor transition in the proximity of an electronic phase separation. In particular we investigate the interplay between superconducting fluctuations and density fluctuations, which…
Superconductivity and polar charge fluctuation are studied in an organic conductor with the dimer-molecule degree of freedom. The extended Hubbard models, where the intra-dimer electronic structure and the inter-dimer Coulomb interactions…
The low energy behaviour of the isotropic t--J ladder system is investigated using exact diagonalization techniques, specifically finding the Drude weight, the charge velocity and the compressibility. By applying the ideas of Luttinger…
We determine the quantum phase diagram of the Hubbard chain with electron-hole symmetric correlated hopping at 1/2- and 1/4-filling using geometric concepts and continuum limit field theory. The long distance behavior of various correlation…
We have studied the extended Hubbard model with pair hopping in the atomic limit for arbitrary electron density and chemical potential. The Hamiltonian considered consists of (i) the effective on-site interaction U and (ii) the intersite…
First principles investigations of the high temperature superconducting system Ba$_2$CuO$_{3+\delta}$, recently discovered at $\delta\approx0.2$ at $T_c=70$ K, are applied to demonstrate the effects of oxygen ordering on the electronic and…
The standard theory of metals, Fermi liquid theory, hinges on the key assumption that although the electrons interact, the low-energy excitation spectrum stands in a one-to-one correspondence with that of a non-interacting system. In the…
Conductions fluctuations (CF) are studied in single layer graphene devices with superconducting source and drain contacts made from aluminium. The CF are found to be enhanced by superconductivity by a factor of 1.4 to 2. This (near)…
The dimensionality of a correlated many-body system has a large impact on its electronic properties. When electrons are confined to one-dimensional chains of atoms their behavior is very different than in higher dimensional systems because…
If phase coherence determines the superconducting transition temperature Tc in the cuprate oxides, it is of great interest to understand the role that dynamics of the phase fluctuation plays in bringing about depletion of the…