Related papers: The electronic specific heat in the pairing pseudo…
Using cluster perturbation theory, it is shown that the spectral weight and pseudogap observed at the Fermi energy in recent Angle Resolved Photoemission Spectroscopy (ARPES) of both electron and hole-doped high-temperature superconductors…
Thermal measurements, such as the entropy and the specific heat, reveal key elementary excitations for understanding the cuprates. In this paper, we study the specific heat measurements on three different compounds La$_{2-x}$Sr$_x$CuO$_4$,…
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…
The two-dimensional attractive Hubbard model is studied in the weak to intermediate coupling regime by employing a non-perturbative approach. It is first shown that this approach is in quantitative agreement with Monte Carlo calculations…
For an electron gas with a $ \delta $-function attraction we investigate the crossover from weak-coupling to strong-coupling superconductivity as well as normal state near the temperature $T^*$, at which the strong coupling produces a…
We outline a partial-fractions decomposition method for determining the one-particle spectral function and single-particle density of states of a correlated electronic system on a finite lattice in the non self-consistent T-matrix…
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…
We describe the high-temperature superconductor La$_{2-x}$Sr$_x$CuO$_4$ in the underdoped regime in terms of a mixed-phase model, which consists of superconducting clusters embedded in the antiferromagnetic matrix. Our work is motivated by…
Detailed doping dependence of the electronic specific heat coefficient gamma is studied for La2-xSrxCuO4 (LSCO) single crystals in the slightly-doped regime. We find that gamma systematically increases with doping, and furthermore, even for…
Evidence that the pseudogap (PG) in a near-optimally doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ sample destroys the BCS logarithmic pairing instability [1] raises again the question of the role of the PG in the high-temperature…
The doping and temperature dependence of the thermodynamic properties in cuprate superconductors is studied based on the kinetic energy driven superconducting mechanism. By considering the interplay between the superconducting gap and…
We investigate pseudo-gap phenomena realized in the BCS pairing model with a long but finite interaction range. We calculate the single-particle self-energy in all order exactly in the temperature range where the superconducting fluctuation…
We investigate pseudogap phenomena in the 2D electron system. Based on the mode-mode coupling theory of antiferromagnetic (AFM) and $d_{x^2-y^2}$-wave superconducting ($d$SC) fluctuations, single-particle dynamics is analyzed. For the…
We investigate theoretically the many-body pairing of a strongly correlated two-dimensional Fermi gas with and without negative confinement-induced effective range. Using a strong-coupling effective field theory in the normal state, we show…
The low energy electronic structure of LaFeAsO1-xHx (0.0 < x < 0.60), the system which exhibits two superconducting domes in its phase diagram, is investigated by utilizing the laser photoemission spectroscopy. From the precise…
A reduction of the density of states near the Fermi energy in the normal state (pseudogap) of high-temperature oxide superconductors is examined on the basis of the two-dimensional tight-binding model with effective interactions due to…
Low temperature specific heat has been measured and extensively analyzed on a series of $La_{2-x}Sr_xCuO_4$ single crystals from underdoped to overdoped regime. From these data the quasiparticle density of states (DOS) in the mixed state is…
In strongly correlated materials, interacting electrons are entangled and form collective quantum states, resulting in rich low-temperature phase diagrams. Notable examples include cuprate superconductors, in which superconductivity emerges…
A new model with a new Hamiltonian is offered as the means for studying properties of a system of strongly correlated electrons. Consideration of the simplest possible situation, namely a system on non-interacting electrons in a two-leg…
We calculate the specific heat of composite fermion system in the half-filled Landau level. Two different methods are used to examine validity of the quasiparticle approximation when the two-body interaction is given by $V(q) = V_0 /…