Related papers: Charge fluctuations close to phase separation in t…
We propose a phenomenological model for high-$T_{c}$ superconductors (HTSC) assuming: (1) a microscopic phase separation between superconducting and normal-metal areas in the overdoped region; and (2) existence of a homogeneous…
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…
Electronic Raman scattering from high- and low-energy excitations was studied as a function of temperature, extent of hole doping, and energy of the incident photons in Bi_2Sr_2CaCu_2O_{8 \pm \delta} superconductors. For underdoped…
The possibility of coexistence of superconductivity (SC) and antiferromagnetic long range order (AFLRO) of the two-dimensional extended $t-J$ model in the very underdoped region is studied by the variational Monte-Carlo (VMC) method. In…
Competition and coexistence of charge orders and superconductivity are hallmarks in many strongly correlated electron systems. Here, we unravel the precise role of charge fluctuations on the superconducting state in the $t$-$t'$-$J$ model…
Superconductivity in the t-J model is studied by extending the recently introduced extremely correlated fermi liquid theory. Exact equations for the Greens functions are obtained by generalizing Gor'kov's equations to include extremely…
The ground state and excitation spectra of the $S=1$ Heisenberg spin chain with hole hopping are investigated by means of the numerical-diagonalization method and by the help of the Zhang-Arovas picture. As for the charge sector, two phases…
The regions of hole concentrations $0 \leq x \alt 0.3$ and temperatures $0.005|t| \leq T \leq 0.02|t|$ are studied in the t-J model of Cu-O planes of perovskite high-$T_c$ superconductors. For this purpose self-energy equations for hole and…
We have performed finite temperature quantum Monte Carlo simulations on the t-Jz model on the square lattice. An on-site potential, representing the effect of external mechanisms, is used to stabilize a state of straight site-centered…
We report on a detailed examination of numerical results and analytical calculations devoted to a study of two holes doped into a two-dimensional, square lattice described by the t-J model. Our exact diagonalization numerical results…
We present an exact diagonalization study of the doping dependence of the single particle Green's function in 16, 18 and 20 site clusters of t-J model. We find evidence for rigid-band behaviour starting from the half-filled case: upon…
We calculate spectral functions within the t-J model as relevant to cuprates in the regime from low to optimum doping. On the basis of equations of motion for projected operators an effective spin-fermion coupling is derived. The self…
Large pulsed magnetic fields up to 60 Tesla are used to suppress the contribution of superconducting fluctuations (SCF) to the ab-plane conductivity above Tc in a series of YBa2Cu3O(6+x). These experiments allow us to determine the field…
A microscopic theory of the electronic spectrum and of superconductivity within the t-J model on the honeycomb lattice is developed. We derive the equations for the normal and anomalous Green functions in terms of the Hubbard operators by…
The dispersion of one hole in an extended $t$-$J$ model with additional hopping terms to second and third nearest neighbours and a frustration term in the exchange part has been investigated. Two methods, a Green's function projection…
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…
By comparing single-particle spectral functions of t-J and Hubbard models with recent angle-resolved photoemission (ARPES) results for LSCO and Nd-LSCO, we can decide where holes go as a function of doping, and more specifically, which type…
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 study of the charge excitations in cuprates is presently an interesting topic because of the development of new and precise x-ray experiments. Based on a large-$N$ formulation of the two-dimensional $t$-$J$ model, which allows us to…
We present a percolation theory for the high-$T_c$ oxides pseudogap and $T_c$ dependence on the hole level. The doping dependent inhomogeneous charge structure is modeled by a distribution which may represent the stripe morphology and yield…