Related papers: Hole and Pair Structures in the t-J model
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…
We study the t-J model with four holes on a 32-site square lattice using exact diagonalization. This system corresponds to doping level x=1/8. At the ``realistic'' parameter J/t=0.3, holes in the ground state of this system are unbound.…
A key step in unraveling the mysteries of materials exhibiting unconventional superconductivity is to understand the underlying pairing mechanism. While it is widely agreed upon that the pairing glue in many of these systems originates from…
Exact diagonalizations of two dimensional small t--J clusters reveal dominant hole-hole correlations at distance $\sqrt{2}$ (ie between holes on next nearest neighbor sites). A new form of singlet $d_{x^2-y^2}$ pair operator is proposed to…
The recent discovery of superconductivity under high pressure in the ladder compound BaFe$_2$S$_3$ has opened a new field of research in iron-based superconductors with focus on quasi one-dimensional geometries. In this publication, using…
Clusters of the two-dimensionnal t--J model with 2 holes and up to 26 sites are diagonalized using a Lanczos algorithm. The behaviour of the binding energy with system size suggests the existence of a finite critical value of J above which…
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…
A two chain ladder model is considered described by the strong coupling $t-t^\prime-J-J^\prime$ Hamiltonian. For the case of two holes moving in a background of antiferromagnetically interacting spins, exact, analytical results are derived…
The problem of two holes in the presence of strong antiferromagnetic fluctuations is revisited using computational techniques. Two-dimensional clusters and 2-leg ladders with up to 32 sites are studied with the Lanczos and Truncated Lanczos…
In strongly correlated quantum materials, the behavior of charge carriers is dominated by strong electron-electron interactions. These can lead to insulating states with spin order, and upon doping to competing ordered states including…
We study repulsive Hubbard and t-J type systems on a square lattice (long believed to capture certain quintessential aspects of the high temperature superconductors). These models (alongside the parent compounds of the high temperature…
Pairing of mobile charge carriers in doped antiferromagnets plays a key role in the emergence of unconventional superconductivity. In these strongly correlated materials, the pairing mechanism is often assumed to be mediated by magnetic…
We present a variational treatment of the ground state of the 2-leg t-J ladder, which combines the dimer and the hard-core boson models into one effective model. This model allows us to study the local structure of the hole pairs as a…
We study the motion of holes in a mixed-dimensional setup of an antiferromagnetic ladder, featuring nearest neighbor hopping $t$ along the ladders and Ising-type spin interactions along, $J_\parallel$, and across, $J_\perp$, the ladder. We…
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…
Holes weakly doped into a four-leg \tj ladder bind in pairs. At dopings exceeding a critical doping of $\delta_c\simeq {1/8}$ four hole clusters are observed to form in DMRG calculations. The symmetry of the ground state wavefunction does…
The recently discussed tendency of holes to generate nontrivial spin environments in the extended two-dimensional t-J model (G. Martins, R. Eder, and E. Dagotto, Phys. Rev. B{\bf 60}, R3716 (1999)) is here investigated using computational…
Results for a doped 3-leg t-J ladder obtained using the density matrix renormalization group are reported. At low hole doping, the holes form a dilute gas with a uniform density. The momentum occupation of the odd band shows a sharp…
For decades, it has remained an open question, whether two dopants in the $t$--$J$ model bind in the strongly correlated regime of small spin couplings versus hopping, $J \ll t$. Here, we investigate this problem in Bethe lattice structures…
The formation of hole pairs in the planar t-J model is studied in the presence of independent {\it dynamic} vibrations of the in-plane oxygen atoms. In-plane (breathing modes) and out-of-plane (buckling modes) displacements are considered.…