Related papers: Effect of a Pseudogap in Strong Coupling d-Wave Su…
It is argued that the superconducting and pseudogaps represent different coexisting phenomena, and this observation speaks against the precursor-superconductivity scenario of the pseudogap; see, V.M. Krasnov et al., Phys. Rev. Lett. 84,…
The real part of the in-plane optical self-energy data in underdoped Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ (Bi-2212) and ortho II YBa$_{2}$Cu$_{3}$O$_{6.5}$ contains new and important information on the pseudogap. Using a theoretical…
We develop a theory of a pseudogap state appearing near the superconductor-insulator transition in strongly disordered metals with attractive interaction. We show that such an interaction combined with the fractal nature of the single…
Recent tunneling observations of a pseudogap in Bi_2Sr_2CaCu_2O_{8+delta} are not necessarily evidence that the pseudogap is associated with superconducting fluctuations. The data are here analyzed as a competition between superconductivity…
The tunneling spectra of high temperature superconductors on Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi-2212) reproducibly show a high bias structure in the form of a dip-hump at voltages higher than the gap voltage. Of central concern is…
Ultrafast broadband transient reflectivity experiments are performed to study the interplay between the non-equilibrium dynamics of the pseudogap and the superconducting phases in Bi$_{2}$Sr$_{2}$Ca$_{0.92}$Y$_{0.08}$Cu$_{2}$O$_{8+\delta}$.…
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…
It has been suggested that the ``pseudogap'' regime in cuprate superconductors, extending up to hudreds of degrees into the normal phase, reflects an incoherent d-wave pairing, with local superconducting order coherent over a finite length…
Understanding the interplay between superconductivity and the pseudogap phase is essential for elucidating the mechanism of high-temperature superconductivity in cuprates. Here we provide direct spatial evidence that these two states are…
We use novel STM techniques in concert to study the doping dependence of electronic structure in Bi-2212. At all dopings, the low energy states are relatively homogenous except for dispersive density-of-states modulations whose properties…
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…
Recently developed numerical methods have enabled the explicit construction of the superconducting state of the Hubbard model of strongly correlated electrons in parameter regimes where the model also exhibits a pseudogap and a Mott…
One of the most essential aspects of cuprate superconductors is a large pseudogap coexisting with a superconducting gap, then some anomalous properties can be understood in terms of the formation of the pseudogap. Within the kinetic energy…
Temperature and doping dependent tunneling spectroscopy on $Bi_2Sr_2CaCu_2O_{8+\delta}$ single crystals has been investigated by using break-junction technique. The results provide direct evidence that the pseudogap persists into heavily…
I begin by briefly reviewing various experimental results on the pseudogap phenomena in underdoped cuprates. I argue that, taken together, all of these lead to a picture of singlet pairing above $T_c$. I then explore the idea that the…
We present results of Raman scattering experiments in differently doped Bi-2212 single crystals. Below Tc the spectra show pair-breaking features in the whole doping range. The low frequency power laws confirm the existence of a…
The single-particle density of states and the tunneling conductance are studied for a two-dimensional BCS-like Hamiltonian with a d_{x^2-y^2}-gap and phase fluctuations. The latter are treated by a classical Monte Carlo simulation of an XY…
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 pseudogap state is one of the peculiarities of the cuprate high temperature superconductors. Here we investigate its presence in BaCo$_{x}$Fe$_{2-x}$As$_{2}$, a member of the pnictide family, with temperature dependent scanning…
The nature of normal state charge-carriers' dynamics and the transition in conduction and gap dimensionalities between 2D and 3D for YBa_2 Cu_3 O_{7-delta} and Bi_2 Sr_2 Ca_{1-x} Y_x Cu_2 O_8 high-T_c superconductors were described by…