Related papers: Abrupt transition in quasiparticle dynamics at opt…
We investigate the properties of cuprate superconductors subject to applied current, using modified Gutzwiller projected d-wave BCS states. The parent states include quasiparticle and quasihole pockets, of variationally determined size,…
The effects of planar hole concentration, p, and in-plane disorder, Zn (y), on the DC resistivity, r(T), of sintered samples of Y_{1-x}Ca_xBa_2(Cu_{1-y}Zn_y)_3O_{7-d} were investigated over a wide doping range by changing both the oxygen…
Doping is one of the most relevant paths to tune the functionality of cuprates, it determines carrier density and the overall physical properties of these impressive superconducting materials. We present an oxygen doping study of…
New electronic Raman and I.R. spectroscopy results from optimally and overdoped high temperature superconducting (HTSC) cuprate systems are interpreted in terms of the negative-U, boson-fermion crossover model. Distinction is made between…
Optimally doped cuprate superconductors are characterized by the presence of superconducting fluctuations in a relatively large temperature region above the critical transition temperature. We reveal here that the effect of thermal…
Bi-based cuprate superconductors are important materials for both fundamental research and applications. As in other cuprates, the superconducting phase in the Bi compounds lies close to an antiferromagnetic phase. Our density functional…
Superconductivity in high temperature superconductors is achieved by introducing charge carriers into cuprate insulators containing CuO$_2$ planes. Perturbation in these CuO$_2$ planes suppresses superconductivity by strongly affecting the…
High temperature superconductors, especially YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO), are considered a key enabling technology towards a clean energy future. Hole doping in YBCO is a prerequisite for the emergence of its unchallenged…
We present studies of the photoexcited quasiparticle dynamics in Tl$_{2}$Ba$_{2}$Ca$_{2}$Cu$_{3}$O$_{y}$ (Tl-2223) using femtosecond optical techniques. Deep into the superconducting state (below 40 K), a dramatic change occurs in the…
The Nernst effect was measured in the electron-doped cuprate superconductor Pr2-xCexCuO4 (PCCO) at four concentrations, from underdoped (x=0.13) to overdoped (x=0.17), for a wide range of temperatures above the critical temperature Tc. A…
A long-standing puzzle is why there is a difference between the optimal doping \delta_{optimal}=0.15 for the maximal superconducting (SC) transition temperature Tc and the critical doping \delta_{critical}=0.19 for the highest superfluid…
Bi2Sr2CaCu2O{8 + \delta} crystals with varying hole concentrations (0.12 < p < 0.23) were studied to investigate the effects of doping on the symmetry and magnitude of the superconducting gap. Electronic Raman scattering experiments that…
A smart meta-superconductor Bi(Pb)SrCaCuO (B(P)SCCO) may increase the critical transition temperature (TC) of B(P)SCCO by electroluminescence (EL) energy injection of inhomogeneous phases. However, the increase amplitude {\Delta}TC…
Non-zero spin orbit coupling has been reported in several unconventional superconductors due to the absence of inversion symmetry breaking. This contrasts with cuprate superconductors, where such interaction has been neglected for a long…
The ubiquitous temperature ($T$)-linear behaviour of the transport scattering rate in the normal state of strongly correlated electron systems is called strange metallicity…
Effect of phase fluctuations on superconducting states with anisotropic order parameters is studied in a BCS like lattice model of cuprate superconductors. The degradation of the mean field transition temperature due to phase fluctuations…
Although initially quite controversial, it has been widely accepted that the Cooper pairs in optimally doped cuprate superconductors have predominantly dx2-y2 wavefunction symmetry. The controversy has now shifted to whether the high-Tc…
High temperature superconductivity in cuprates is realized by doping the Mott insulator with charge carriers. A central issue is how such an insulating state can evolve into a conducting or superconducting state when charge carriers are…
Recent reflectivity measurements provide evidence for a "violation" of the in-plane optical integral in the underdoped high-T_c compound Bi_2Sr_2CaCu_2O_{8+\delta} up to frequencies much higher than expected by standard BCS theory. The sum…
We use angle-resolved photoemission spectroscopy applied to deeply underdoped cuprate superconductors Bi2Sr2(Ca,Y)Cu2O8 (Bi2212) to reveal the presence of two distinct energy gaps exhibiting different doping dependence. One gap, associated…