Related papers: Superconducting gap for a 2-leg t-J ladder
We study the low-energy physics of planar Josephson junction structures realized in a quasi-two dimensional semiconductor system proximity-coupled to narrow superconducting films. Using both a recursive Green's function approach and an…
The condensation energy and the specific heat jump of a two-dimensional Hubbard model, suitable to discuss high-$T_c$ superconductors, is studied. In this work, the Hubbard model is investigated by the Green's function method within a…
In previous studies, we proposed a scaling ansatz for electron-electron interactions under renormalization group transformation. With the inclusion of phonon-mediated interactions, we show that the scaling ansatz, characterized by the…
We evaluate numerically several superconducting correlation functions in a generalized $t-J$ model derived for hole-doped CuO$_2$ planes. The model includes a three-site term $t''$ similar to that obtained in the large $U$ limit of the…
We investigate excitation energies of hyperbolically deformed S = 1 spin chains, which are specified by the local energy scale f_j^{~} = \cosh j \lambda, where j is the lattice index and \lambda is the deformation parameter. The elementary…
We present an exact diagonalization study of the single particle spectral function in the so-called t-t'-t''-J model in 2D. As a key result, we find that unlike the `pure' t-J model, hole doping leads to a major reconstruction of the…
In Chapter 11 we present Fermi-gas approach for the search of s-wave and p-wave superfluidity in three-dimensional solutions of He-3 in He-4 and in He-3 submonolayers. In Chapter 13 on the basis of the anisotropic and isotropic t-J models…
We compute the exact partition function of 2d Ising spin glasses with binary couplings. In these systems, the ground state is highly degenerate and is separated from the first excited state by a gap of size 4J. Nevertheless, we find that…
The nature of normal state charge-carriers' dynamics and the transition in conduction and gap dimensionalities between 2D and 3D for YBa_2 Cu_3 O_{7-delta} and Bi_2 Sr_2 Ca_{1-x} Y_x Cu_2 O_8 high-T_c superconductors were described by…
We theoretically investigate the electric transport in the pseudogap state of High-Tc cuprates. Starting from the repulsive Hubbard model, we perform the microscopic calculation to describe the pseudogap phenomena which are induced by the…
Some ground state static correlation functions for the $1/r^2$ exchange $t-J$ model of Kuramoto and Yokoyama are calculated exactly. The correlations calcualted are the pair distribution functions between two down spins, a down spin and a…
A method to calculate exact Green's functions on lattices in various dimensions is presented. Expressions in terms of generalized hypergeometric functions in one or more variables are obtained for various examples by relating the resolvent…
With a super-high-efficient numerical algorithm, we are able to self-consistently calculate the Green's function in the renormalized-ring-diagram approximation for a two-dimensional electron system with long-range Coulomb interactions. The…
The spectral functions and corresponding self energies are calculated within the planar t-t'-J model as relevant to hole-doped cuprates using the exact diagonalization method at finite temperatures, combined with the averaging over twisted…
Using the strong coupling diagram technique for calculating the electron Green's function of the two-dimensional Hubbard model we have summed infinite sequences of ladder diagrams, which describe interactions of electrons with spin and…
We present a nonperturbative method for deriving a quasiparticle description of the low-energy excitations in the t-J model for strongly correlated electrons. Using the exact diagonalization technique we evaluated exactly the spectral…
The perturbative QCD predictions concerning deep inelastic scattering at low $x$ are summarized. The theoretical framework based on the leading log $1/x$ resummation and $k_t$ factorization theorem is described and some recent developments…
We construct, using fermionic functional integrals, thermodynamic Green's functions for a weakly coupled fermion gas whose Fermi energy lies in a gap. Estimates on the Green's functions are obtained that are characteristic of the size of…
We study the phase diagram of a 2-leg bond-alternation spin-(1/2, 1) ladder for two different configurations using a quantum renormalization group approach. Although d-dimensional ferrimagnets show gapless behavior, we will explicitly show…
We critically review the fast algorithms for the numerical study of two--dimensional Josephson junction arrays and develop the analogy of such systems with electrostatics. We extend these procedures to arrays with bus--bars and defects in…