相关论文: Spectral functions and pseudogap in the t-J model

Preformed pairs above $T_c$ and the two-gap scenarios are two main proposals for describing the low doping pseudogap phase of high-$T_c$ cuprates. Very recent angle-resolved photoemission experiments have shown features which were…

The generic band structure of high-T$_C$ copper oxides is simulated by the nearly free-electron model (NFE) in two dimensions (2-D) with parameters from band calculations. Interaction between phonons and spin waves will cause potential…

The physical origin of cuprate high-temperature superconductor pseudogaps remains debatable. We point out that the indication of such excitation is hidden in the usual expression for the quasiparticle energy. It can be realized on a…

Using the description in terms of the Hubbard operators hole and spin Green's functions of the two-dimensional t-J model are calculated in an approximation which retains the rotation symmetry of the spin susceptibility in the paramagnetic…

Cuprate high-T_c superconductors on the Mott-insulating side of "optimal doping" (with respect to the highest T_c's) exhibit enigmatic behavior in the non-superconducting state. Near optimal doping the transport and spectroscopic properties…

We perform a fluctuation analysis of the pairing interaction in the hole-doped Hubbard model within the dynamical cluster approximation. Our analysis reveals that spin-fluctuation-mediated pairing differs qualitatively in the over- and…

The t-J_z model is the strongly anisotropic limit of the t-J model which captures some general properties of the doped antiferromagnets (AF). The absence of spin fluctuations simplifies the analytical treatment of hole motion in an AF…

We discuss the application of the two-band spin-dopon representation of the t-J model to address the issue of the Fermi surface reconstruction observed in the cuprates. We show that the electron no double occupancy (NDO) constraint plays a…

A spin-charge recombination route to superconductivity, proposed earlier (1992)], is examined using the Schwinger boson representation of the t-J model. The representation is known to work well at half-filling. It was shown in the earlier…

To explain the experimental spectra for angle resolved photoemission we consider a modified t-J model. The modified model includes next nearest (t') and next next nearest (t'') hopping as well as Hubbard model corrections to the spectral…

Based on a variational approach, we propose that there are two kinds of low energy states in the t-J type models at low doping. In a quasi-particle state an unpaired spin bound to a hole with a well-defined momentum can be excited with spin…

We propose an explanation of several experimental features related to the ``pseudogap'' in HTS cuprates in terms of a spin-charge gauge theory approach to the t-J model. The metal-insulator crossover as temperature decreases is explained…

The electron spectrum in the normal phase of cuprates is analyzed in terms of the boson-fermion model. It is argued that the existence of the uncondensed pairs and the quasi-two-dimensional nature of the crystal structure are responsible…

The effect of the additional second neighbor hopping t' on the charge dynamics of the t-J model in the underdoped regime is studied within the fermion-spin theory. The conductivity spectrum of the t-t'-J model shows the low-energy peak and…

The influence of spin and charge fluctuations on spectra of the two-dimensional fermionic Hubbard model is considered using the strong coupling diagram technique. Infinite sequences of diagrams containing ladder inserts, which describe the…

We study the frequency-dependent structure of electronic self-energy in the pseudogap and superconducting states of the two-dimensional Hubbard model. We present the self-energy calculated with the cellular dynamical mean-field theory…

Using an energy-momentum dispersion for Bi2Sr2CaCu2O8 obtained from angle-resolved photoelectron spectroscopy we show that the shrinking Fermi arc model of the pseudogap is inconsistent with Raman scattering below Tc and specific heat near…

We elaborate on several observable consequences of the Quantum-Critical-Point scenario. In particular we show that the strong k-dependent scattering of the quasiparticles with the quasi-critical charge and spin fluctuations reproduces the…

Pseudogap phenomena and the formation of Fermi arcs in underdoped cuprates are numerically studied in the presence of phase fluctuations that are simulated by an XY model. Most importantly the spectral function for each Monte Carlo sample…

The density fluctuation spectrum $N({\bf k},\omega)$ is calculated for the t-J model in the low-doping regime using a slave-fermion method for the constrained fermions. The obtained results for $N({\bf k},\omega)$ are in good agreement with…