Related papers: Locating the missing superconducting electrons in …
From systematic analysis of the high pulsed magnetic field resistance data of La$_{2-x}$Sr$_x$CuO$_{4}$ thin films, we extract an experimental phase diagram for several doping values ranging from the very underdoped to the very overdoped…
Superflow in a phenomenological tight-binding model for the superconducting state of some High-temperature superconductors is discussed thoroughly. The formalism used is explicitly gauge-invariant and currents are computed exactly within…
Since the discovery of high-temperature superconductivity in the cuprates a theoretical understanding of their phase diagram has remained one of the major outstanding problems in condensed matter physics. Here we propose an effective…
We begin with an overview of the experimental results for the temperature and doping dependences of the optical-conductivity spectral weight in cuprate superconductors across the whole phase diagram. Then we discuss recent attempts to…
Within the framework of the kinetic energy driven superconducting mechanism, the effect of the extended impurity scatterers on the quasiparticle transport of cuprate superconductors in the superconducting state is studied based on the nodal…
The superfluid density of overdoped La$_{2-x}$Sr$_x$CuO$_4$ thin films of high quality have been measured with Tc (defined by the onset of the Meissner effect) from 5.1 to 41.6 K by Bosovic et al. Given this Tc the superfluid density shows…
We measured the terahertz (THz) complex conductivity of Ca doped YBa_{2}Cu_{3}O_{7-\delta} thin films in the frequency range of 0.1 to 3 THz (3 to 100 cm^{-1}) and at a temperature range of 20 to 300 K. The films were measured using both…
The quasiparticle density of states (DOS), the energy gap, the superfluid density $\rho_s$, and the localization effect in the s- and d-wave superconductors with non-magnetic impurity in two dimensions (2D) are studied numerically. For…
We have systematically studied the transport properties of the La$_{2-x}$Y$_{x}$CuO$_{4}$(LYCO) films of T'-phase ($0.05\leq x \leq 0.30$). In this nominally "undoped" system, superconductivity was acquired in certain Y doping range…
Conventional superconductors are characterized by a single energy scale, the superconducting gap, which is proportional to the critical temperature Tc . In hole-doped high-Tc copper oxide superconductors, previous experiments have…
One of the first theoretical proposals for understanding high temperature superconductivity in the cuprates was Anderson's RVB theory using a Gutzwiller projected BCS wave function as an approximate ground state. Recent work by Paramekanti,…
The physical properties of low energy superconducting quasiparticles in high- $T_c$ superconductors are examined using magnetic penetration depth and specific heat experimental data. We find that the low energy density of states of…
Superfluid condensation can fundamentally be different from that predicted by the Bardeen-Cooper-Schrieffer (BCS) theory. In a broad class of low-carrier-density superconductors, such as granular aluminum, doped nitrides, and high-Tc…
The in-plane optical conductivity of Bi2Sr2CaCu2O8+d thin films with small carrier density (underdoped) up to large carrier density (overdoped) is analyzed with unprecedented accuracy. Integrating the conductivity up to increasingly higher…
We study a simple BCS-like model which describes unconventional superconductivity on the basis of an electron-electron attraction corresponding to the delta-shell potential: $U(r) = -g \delta(r-r_0)$. It predicts a $T_c$ vs. doping behavior…
The challenge of understanding high-temperature superconductivity has led to a plethora of ideas, but 30 years after its discovery in cuprates, very few have achieved convincing experimental validation. While Hubbard and t-J models were…
In this paper we compare two broad classes of theories for the pseudogap in cuprate superconductors. The comparison in made in reference to measurements of the superfluid density, $\rho_s(T,x)$, in $YBa_2CuO_{7- \delta}$ films having a wide…
Experimental evidence on high-Tc cuprates reveals ubiquitous charge density wave (CDW) modulations, which coexist with superconductivity. Although the CDW had been predicted by theory, important questions remain about the extent to which…
Many years of intense research on cuprate superconductors have led to several discoveries, such as the pseudogap and charge density waves (CDW), yet a complete theory is still lacking. By analyzing some experiments and performing…
It is shown that many anomalies observed in underdoped cuprates, including anomalous spectral weight transfer and a large pseudogap, appear to have a common nature due to both the cluster structure of the underdoped phase and the specific…