Related papers: Pseudogap Phase: Exchange Energy Driven vs. Kineti…
Within the t-J model, the charge dynamics of copper oxide materials in the underdoped regime is studied based on the fermion-spin theory. It is shown that both in-plane charge dynamics and c-axis charge dynamics are mainly governed by the…
High-Tc superconducting materials (HTSC) have anomalous properties such as the pseudo-gap or spin-gap etc., in Hall coefficient, 1/T1T and the density of states etc. First including effects of strong on-site repulsion between d-electrons at…
Thermodynamic quantities are derived for superconducting and pseudogap regimes by taking into account both amplitude and phase fluctuations of the pairing field. In the normal (pseudogap) state of the underdoped cuprates, two domains have…
It is proposed that the upper pseudogap phase (UPP) observed in the high-Tc cuprates correspond to the formation of spin singlet pairing under the bosonic resonating-valence-bond (RVB) description. We present a series of evidence in support…
Within the kinetic energy driven superconducting mechanism, the effect of the additional second neighbor hopping t' on the superconducting state of the t-J model is discussed. It is shown that t' plays an important role in enhancing the…
Using the two-particle self-consistent approach and cluster perturbation theory for the two-dimensional t-t'-t''-U Hubbard model, we discuss weak- and strong-coupling mechanisms for the pseudogap observed in recent angle resolved…
An intricate interplay between superconductivity, pseudogap and Mott transition, either bandwidth driven or doping driven, occurs in materials. Layered organic conductors and cuprates offer two prime examples. We provide a unified…
The mechanism of high-Tc superconductivity is investigated with interests on the microscopic aspects of the condensation energy. The theoretical analysis is performed on the basis of the FLEX approximation which is a microscopic description…
The relationship between the pseudogap and superconductivity remains a central puzzle in the physics of cuprates. Hydrostatic pressure provides a clean tuning parameter free from chemical disorder, yet probing the microscopic energy scales…
Superconductivity in cuprate superconductors occurs upon charge-carrier doping Mott insulators, where a central question is what mechanism causes the loss of electrical resistance below the superconducting (SC) transition temperature? In…
We describe the spectral properties of underdoped cuprates as resulting from a momentum-dependent pseudogap in the normal state spectrum. Such a model accounts, within a BCS approach, for the doping dependence of the critical temperature…
We present an resonating valence bond (RVB) theory of superconductivity for the Hubbard--Heisenberg model on an anisotropic triangular lattice. We show that these calculations are consistent with the observed phase diagram of the…
The charge spin-separation, pseudogap formation and phase diagrams are studied in two and four site Hubbard clusters using analytical diagonalization and grand canonical ensemble method in a multidimensional parameter space of temperature,…
A model incorporating simultaneous superconducting and lattice instabilities has been studied in detail to estimate the nature of coupling and inter-play between them. The phase diagram is obtained in the temperature-filling plane at…
The SU(2)xU(1) Chern-Simons spin-charge gauge approach developed earlier to describe the transport properties of the cuprate superconductors in the ``pseudogap'' regime, in particular, the metal-insulator crossover of the in-plane…
We study the phase diagram of the t-J model using a mean field type approximation within the Baym-Kadanoff perturbation expansion for Hubbard $X$-operators. The line separating the normal state from a d-wave flux or bond-order state starts…
There are processes in nature that resemble a true force but arise due to the minimization of the local energy. The most well-known case is the exchange interaction that leads to magnetic order in some materials. We discovered a new similar…
The t-J model is a paradigmatic model for the study of strongly correlated electron systems. In particular, it has been argued that it is an appropriate model to describe the cuprate high-Tc superconductors. It turns out that a…
Strongly correlated electrons systems may exhibit a variety of interesting phenomena, for instance, superconductivity and pseudogap, as is the case of cuprates and pnictides. In strongly correlated electron systems, it is considered…
A simple model to describe the energetic phase diagram of electron-doped cuprate superconductor is developed. Interband pairing operates between the UHB and the defect states created by doping and supplied by both extincting HB-s. Two…