Related papers: Anomalous c-axis charge dynamics in copper oxide m…
The discovery of superconductivity in copper oxide compounds has attracted considerable attention over the past three decades. The high transition temperature in these compounds, exhibiting proximity to an antiferromagnetic order in their…
We study the evolution of the optical conductivity in the t-J model with temperature and doping using the Extended Dynamical Cluster Approximation. The cluster approach results in an optical mass which is doping independent near half…
High-$T_{\rm C}$ superconductors show anomalous transport properties in their normal states, such as the bad-metal and pseudogap behaviors. To discuss their origins, it is important to speculate whether these behaviors are…
Charge density waves are a common occurrence in all families of high critical temperature superconducting cuprates. Although consistently observed in the underdoped region of the phase diagram and at relatively low temperatures, it is still…
We report on infrared studies of the c-axis electrodynamics of Tl-Ba-Cu-O (Tl-2201) crystals. A sum rule analysis reveals spectral weight shifts that can be interpreted as a kinetic energy change at the superconducting transistion. In…
The electromagnetic response of a system with two planes per unit cell involves, in addition to the usual intraband contribution, an added interband term. These transitions affect the temperature dependence and the magnitude of the zero…
We use the three-dimensional Josephson junction array system as a model for studying the temperature dependence of the c-axis resistivity of high temperature superconductors, in the presence of an external magnetic field H applied in the…
A simple model of cuprate superconductivity with an electron spectrum prepared by doping is developed. The pair-transfer interaction couples the itinerant band with two components ("hot'' and "cold'') of the defect subsystem. There are…
We report the discovery of phenomena consistent with bad-metal relaxation dynamics in the metallic regime of an optical-lattice Hubbard model. The transport lifetime induced by inter-particle scattering for a mass current of atoms excited…
The unusual non-linear effects in hopping conduction of single-crystal La_{2}CuO_{4 + \delta} with excess oxygen has been observed. The resistance is measured as a function of applied voltage U (10^{-3} V - 25 V) in the temperature range 5…
Recently observed $c$-axis optical sum rule violations indicate non-Fermi liquid in-plane behavior. For coherent $c$-axis coupling, the observed flat, nearly frequency independent $c$-axis conductivity $\sigma_{1}(\omega)$ implies a large…
The strange metal phase of optimally and overdoped cuprates exhibits a number of anomalous transport properties: unsaturating linear T resistivity, distinct relaxation times for Hall angle and resistivity, temperature dependent anisotropic…
SQUID magnetization measurements in oriented powders of Y$_{1-x}$Ca$_{x}$Ba$% _{2}$Cu$_{3}$O$_{y}$, with $x$ ranging from 0 to 0.2, for $y\approx 6.1$ and $y\approx 6.97$, have been performed in order to study the doping dependence of the…
The microscopic origin of the pseudogap state which exists in the underdoped cuprates remains unknown. The $c$-axis properties in the pseudogap regime are particularly anomalous. We use a recently proposed model of a $d$-density wave which…
The ground state of the t-t'-J ladder with four legs favors a striped charge distribution for the parameters corresponding to hole-doped cuprate superconductors. We investigate the dynamical spin and charge structure factors of the model by…
We propose an explanation of the observed dependence of the maximal critical temperature $T_{c,max}$ on the number of conducting layers $n$ in layered copper-oxide superconductors within the preformed pair mechanism. Copper-oxygen planes…
Based on an unconventional Fermi liquid model, we present several results on the optimally doped and overdoped cuprate superconductors. For the normal state, we provide an analytic demonstration, backed by self-consistent Baym-Kadanoff (BK)…
Within the t-J model, the mechanism of superconductivity in doped cuprates is studied based on the partial charge-spin separation fermion-spin theory. It is shown that dressed holons interact occurring directly through the kinetic energy by…
To fathom the mechanism of high-temperature ($T_{\rm c}$) superconductivity, the dynamical vertex approximation (D$\Gamma$A) is evoked for the two-dimensional repulsive Hubbard model. After showing that our results well reproduce the…
We follow the evolution of Copper and Oxygen two-hole excitations, in optimally doped (Ca$_{x}$La$_{1-x}$)(Ba$_{1.75-x}$La$_{0.25+x} $)Cu$_{3}$O$_{y}$ for $x=0.1$ and $x=0.4$. The spectra have contributions from band states as well as a…