相关论文: Pairing Correlations on t-U-J Ladders
Using density matrix renormalization group calculations, we compare results obtained for the t-J, one-band Hubbard and three-band Hubbard models of a two-leg CuO ladder. Spin and charge gaps, pair binding energies, and effective pair…
We observe an enhanced visibility of charge-density-wave correlations in a cold-atom realization of the attractive Hubbard model following a rapid boost of the interaction strength. The interaction boost associates nonlocal pairs into…
Spin gaps in coupled $t$-$J$ ladders are investigated by exact diagonalization of small clusters up to 4$\times$8 sites. At half-filling, the numerical results for the triplet excitation spectrum are in very good agreement with a second…
We introduce a new model and mechanism of high temperature pairing in stripes. We propose a way to unambiguously test it by numerical simulations. For example, the implementation of our mechanism in a 6-leg t-J ladder model has the effect…
We numerically investigate a bosonic representation for hole pairs on a two-leg t-J ladder where hard core bosons on a chain represent the hole pairs on the ladder. The interaction between hole pairs is obtained by fitting the density…
The stability of hole bound states in the t-J model including short-range Coulomb interactions is analyzed using computational techniques on ladders with up to $2 \times 30$ sites. For a nearest-neighbors (NN) hole-hole repulsion, the…
The question of whether one should speak of a "pairing glue" in the Hubbard and t-J models is basically a question about the dynamics of the pairing interaction. If the dynamics of the pairing interaction arises from virtual states, whose…
Exact Diagonalization calculations are presented for the t-J model in the presence of a uniform magnetic field. Results for 2xL ladders (L=8,10,12) and 4x4 square clusters with 1 and 2 holes indicate that the diamagnetic response to a…
We present a comparative study of the Hubbard and $t-J$ models far away from half-filling. We show that, at such fillings the $t-J$ Hamiltonian can be seen as an effective model of the repulsive Hubbard Hamiltonian over the whole range of…
We study signatures of superconductivity in a 2--leg "checkerboard" Hubbard ladder model, defined as a one--dimensional (period 2) array of square plaquettes with an intra-plaquette hopping $t$ and inter-plaquette hopping $t'$, using the…
We perform the numerical equivalent of a phase sensitive experiment on doped $t-J$ ladders. We apply proximity effect fields with different complex phases at both ends of an open system and we study the transport of Cooper pairs. Measuring…
The properties of the two-chain Hubbard Model doped away from half-filling are investigated. The charge gap is found to vanish, but a finite spin gap exists over a range of interchain hopping strength $t_\perp$. In this range, there are…
A possible pairing mechanism for high temperature superconductivity in the cuprates is discussed.
Several experiments in the context of ladder materials have recently shown that the study of simple models of anisotropic ladders (i.e. with different couplings along legs and rungs) is important for the understanding of these compounds. In…
Using numerical diagonalization of a 4x4 cluster, we calculate on-site s, extended s and d pairing correlation functions (PCF) in an effective generalized Hubbard model for the cuprates, with nearest-neighbor correlated hopping and next…
We study the effect of the correlated hopping term and the intersite Coulomb interaction term on principal features of the $d$-$wave$ superconducting (SC) state, in both the electron and hole doped regimes within the t-J-U model. In our…
Pairing in superconductors occurs in a variety of channels and can be produced by various mechanisms. Here, we show that, in the presence of strong correlations, a novel singlet-pair superconducting phase can occur in ladder geometries with…
Using 4-site plaquette or rung basis decomposition, the CORE method is applied to 2-leg and 4-leg t-J ladders and cylinders. Resulting range-2 effective hamiltonians are studied numerically on periodic rings taking full advantage of the…
Motivated by Resonant X-ray scattering experiments in cuprate ladder materials showing charge order modulation of period $\lambda=3$ and 5 at specific hole densities, we investigate models involving the electronic t-J ladders and bosonic…
Hubbard ladders are an important stepping stone to the physics of the two-dimensional Hubbard model. While many of their properties are accessible to numerical and analytical techniques, the question of whether weakly hole-doped Hubbard…