Related papers: Two-Dimensional t-J Model at Low Electron Density
We study the so-called nonmagnetic phases (dimer and flux states) in the t-J model below half filling. We present a new phase diagram, at zero and finite temperature, that includes broad areas of phase coexistence (dimer-flux or…
The superconducting state around a well isolated nonmagnetic impurity in the high-Tc superconductors is studied using the two-dimensional t-J model. The spatial dependence of the order parameter and the local density of states are obtained…
We investigate a t-J ladder model by numerical diagonalization method. By calculating correlation functions and assuming the Luttinger liquid relation, we obtained a possible phase diagram of the ground state as a function of J/t and…
Superconducting correlations in the two dimensional ${\rm t-J}$ model at zero temperature are evaluated using numerical techniques. At the fermionic density $\langle n \rangle \sim 1/2$, strong signals of $\dx2y2$ superconductivity were…
Spatial dependencies of the pair potential and the local density of states near the surfaces of $d_{x^{2}-y^{2}}$-wave superconductors are studied theoretically. The calculation is based on the t-J model within a mean-field theory with…
Variational and diffusion quantum Monte Carlo methods are employed to investigate the zero-temperature phase diagram of the three-dimensional homogeneous electron gas at very low density. Fermi fluid and body-centered cubic Wigner crystal…
We compute the ground-state fidelity and various correlations to gauge the competition between different orders in two-dimensional t-J-type models. Using exact numerical diagonalization techniques, these quantities are examined for (i) the…
The ground state of 2D electrons in high magnetic field is studied by the density matrix renormalization group method. The ground state energy, excitation gap, and pair correlation functions are systematically calculated at various fillings…
We investigate the nature of the ground state of the one-dimensional t-J model coupled to adiabatic phonons by use of the Lanczos technique at quarter filling. Due to the interplay between electron-electron and electron-phonon interactions,…
The initial trial wave function used in a simple ground-state projection method, the power method, is systematically improved by using Lanczos algorithm. Much faster convergence to the ground state achieved by using these wave functions…
We present an exact diagonalization study of the low energy singlet and triplet states for both 1D and 2D t-J model. A scan of the parameter ratio J/t shows that for nearly all low energy states in both 1D and 2D the excitation energy takes…
We study the t-J model in one dimension by numerically projecting the true ground state from a Luttinger liquid trial wave function. We find the model exhibits Luttinger liquid behavior for most of the phase diagram in which interaction…
We investigate the ground state properties of the $t-J$ model on a two leg ladder with anisotropic couplings ($t,\alpha=J/t$) along rungs and ($t',\alpha'=J'/t'$) along legs. We have implemented a cluster approach based on 4-site plaqettes.…
The ground-state phase diagram of the asymmetric Hubbard model is studied in one and two dimensions by a well-controlled numerical method. The method allows to calculate directly the probabilities of particular phases in the approximate…
It is well known that the dielectric constant of two-dimensional (2D) electron system goes negative at low electron densities. A consequence of the negative dielectric constant could be the formation of the droplet state. The droplet state…
The emergence of phase separation is investigated in the framework of a 2D t-J model by means of a variational product ansatz, which covers the infinite lattice by two types of L x L clusters. Clusters of the first type are completely…
The phase diagram of the unconstrained $t-J$ model is calculated using the random phase approximation. It is found that the extended $s$ and the $d_{x^2-y^2}$-channels are {\em not} degenerate near half filling. Extended $s$-pairing with a…
Series expansions at T=0 are used to study properties of the half-filled $t-J$ ladder doped with one or two holes, and at quarter filling. Dispersion curves are obtained for one-hole symmetric and antisymmetric (bonding and antibonding)…
An anisotropic t-J-U model Hamiltonian is used to model electron behaviour in quasi-2d materials in the dilute limit, and as a highly simplified representation of the weakly coupled CuO2 planes of the high-Tc cuprates we model the very poor…
The phase diagram of the two-leg t-Jz ladder is explored, using the density matrix renormalization group method. Results are obtained for energy gaps, electron density profiles and correlation functions for the half-filled and…