Related papers: Hole and Pair Structures in the t-J model
The spin and charge excitations of the t--J ladder are studied by exact diagonalization techniques for several electron densities. The various modes are classified according to their spin (singlet or triplet excitations) and their parity…
Previous studies have shown that bipartite Hubbard systems with inhomogeneous hopping amplitudes can exhibit higher pair-binding energies than the uniform model. Here we examine whether this result holds for systems with a more generic band…
The two-dimensional t-J model in a staggered field is studied by exact diagonalization of small clusters. For the low-hole-density region and a realistic value of J/t, it is found that the presence of a staggered field strengthens the…
We investigate the Emery model on several ladder-like lattices including two legs of copper d-orbitals and various numbers of oxygen p-orbitals. Pair binding energy, pair spatial structure, density distribution, and pairing correlation…
The t-J model is regarded as a canonical model of spin-singlet pairing induced by the {\em kinetic exchange interaction} responsible also for an antiferromagnetic ordering in the strongly correlated narrow-band systems. In the orbitally…
The distribution of holes in Sr$_{14-x}$Ca$_x$Cu$_{24}$O$_{41}$ (SCCO) is revisited with semi-emperical reanalysis of the x-ray absorption (XAS) data and exact-diagonalized cluster calculations. A new interpretation of the XAS data leads to…
An explicit $\textit{spatial}$ localization of a hole is shown in a two-leg $t$-$J$ ladder in the presence of a staggered chemical potential, which still retains a translational symmetry, by density matrix renormalization group method.…
The bilayer Hubbard model with an intra-layer hopping $t$ and an inter-layer hopping $t_\perp$ provides an interesting testing ground for several aspects of what has been called unconventional superconductivity. One can study the type of…
Here we examine various aspects of the pairing mechanism for two models, the two-dimensional and two-leg ladder Hubbard models. Both of these models exhibit pairing correlations with d_{x^2-y^2} symmetry. However, the undoped insulating…
We propose a paring mechanism between holes in the dilute limit of doped frustrated Mott insulators. Hole pairing arises from a hole-hole-magnon three-body bound state. This pairing mechanism has its roots on single-hole kinetic energy…
By paying attention to the hole-doped two-dimensional systems of antiferromagnetically (strongly) correlated electrons, we discuss the cause of hole-rich phase formation in association with phase separation. We show that the phase diagram…
Numerical calculations illustrate the effect of the sign of the next nearest-neighbor hopping term t' on the 2-hole properties of the t-t'-J model. Working mainly on 2-leg ladders, in the -1.0 < t'/t < 1.0 regime, it is shown that…
We examine spectral properties of doped holes dressed with surrounding spin cloud in the t-J model. These composite-hole excitations well characterize prominent band structures in the angle-resolved photoemission spectrum. In…
We introduce a Hubbard model on a particular class of geometries, and consider the effect of doping the highly spin-degenerate Mott-insulating state with a microscopic number of holes in the extreme strong-coupling limit. The geometry is…
Expressions for generalized charge stiffness constant at zero temperature are derived corresponding to low dimensional hole doped quantum antiferromagnets, describable by the t-J-like models, with a view to understanding fermionic pairing…
We implement the contractor-renormalization method to study the checkerboard Hubbard model on various finite-size clusters as function of the inter-plaquette hopping t' and the on-site repulsion U at low hole doping. We find that the…
A chemical potential difference between the legs of a two-leg ladder is found to be harmful for Cooper pairing. The instability of superconductivity in such systems is analyzed by compairing results of various analytical and numerical…
We implement the coupled cluster method to very high orders of approximation to study the spin-$\frac{1}{2}$ $J_{1}$--$J_{2}$ Heisenberg model on a cross-striped square lattice. Every nearest-neighbour pair of sites on the square lattice…
The two-layer square lattice quantum antiferromagnet with spins 1/2 shows a magnetic order-disorder transition at a critical ratio of the interplane to intraplane couplings. We investigate the dynamics of a single hole in a bilayer…
Effective models of hard-core hole pair bosons and triplets are derived from the t-J model in ladders and on the square lattice by performing a change from site to dimer basis. The Hilbert space is truncated by projecting out…