Related papers: Strong- versus Weak-Coupling Paradigms for Cuprate…
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…
We calculate superfluid density for a dirty d-wave superconductor. The effects of impurity scattering are treated within the self-consistent t-matrix approximation, in weak-coupling BCS theory. Working from a realistic tight-binding…
We numerically analyze superconductivity (SC) in the cuprate superconductors by using ab initio effective Hamiltonians consisting of the antibonding combination of Cu $3d_{x^2-y^2}$ and O $2p_{\sigma}$ orbitals. We perform variational Monte…
Extensive ARPES and low-energy inelastic neutron scattering studies of cuprate superconductors can be successfully described using a weak-coupling theory in which quasiparticles on a square lattice interact via scalar and spin-dependent…
We briefly review a theory for the cuprates that has been recently proposed based on the movement and interaction of holes in antiferromagnetic (AF) backgrounds. A robust peak in the hole density of states (DOS) is crucial to produce a…
High superconducting transition temperature is favorable for the applications of superconductors. Some cuprate superconductors have the transition temperatures above 100 K, such as the Hg- or Tl-based 1223 and 1234 phases, but many of them…
We report on the temperature-dependent optical response of thin films of YBa2Cu3O7-{\delta} (YBCO) in the visible spectral range under cryogenic conditions. Specifically, we observe an increase in transmittance near the superconducting…
The influence of the hydrostatic pressure P up to 0.95 GPa on the excess conductivity and the pseudogap {\Delta}*(T) in optimally doped YBCO single crystals (T_c = 91.1K at ambient pressure) is investigated by electrical resistivity…
We report transport measurements using pulsed magnetic fields to suppress the superconducting fluctuations (SCF) conductivity in a series of YBa_2Cu_3O_(6+x) samples. These experiments allow us altogether to measure the temperature T'c at…
Thin films of the optimally electron-doped $T'$-phase superconductor La$_{1.89}$Ce$_{0.11}$CuO$_{4\pm \d}$ are investigated by dilute Co doping, formed as La$_{1.89}$Ce$_{0.11}$(Cu$_{1-x}$Co$_{x}$)O$_{4\pm\d}$ (LCCCO) with $x$ = 0.01 --…
We present experimental results for the in-plane resistivity of the electron-doped cuprate superconductor $La_{2-x}Ce_xCuO_4$ above its transition temperature $T_c$ as a function of Ce doping x and temperature. For the doping x between 0.11…
We review application of the SU(4) model of strongly-correlated electrons to cuprate and iron-based superconductors. A minimal self-consistent generalization of BCS theory to incorporate antiferromagnetism on an equal footing with pairing…
This review gives a rather general discussion of high temperature superconductors as an example of a strongly correlated material. The argument is made that in view of the many examples of unconventional superconductors discovered in the…
We present low-temperature thermal conductivity measurements on the cuprate Tl_2Ba_2CuO_{6+delta} throughout the overdoped regime. In the T -> 0 limit, the thermal conductivity due to d-wave nodal quasiparticles provides a bulk measurement…
The key ingredients in any superconductor are the Cooper pairs, in which two electrons combine to form a composite boson. In all conventional superconductors the pairing strength alone sets the majority of the physical properties including…
We study angular-dependent magnetoresistance in a low $T_c$ layered cuprate Bi$_{2.15}$Sr$_{1.9}$CuO$_{6+\delta}$. The low $T_c$ ~ 4 K allows complete suppression of superconductivity by modest magnetic fields and facilitate accurate…
We report on measurements of the doping dependence of the upper critical field $H_{c,2}$ in 50 nm thick YBa$_2$Cu$_3$O$_{7-\delta}$ films. The films are untwinned and are characterized by a small in-plane compressive strain. We find that…
To elucidate how the temperature dependence of the resistivity anisotropy of the cuprate superconductors changes with hole doping, both the in-plane and the out-of-plane resistivities (\rho_{ab} and \rho_{c}) are measured in a series of…
We report magnetic field dependent magnetization and microwave impedance measurements on a MgB2 superconductor prepared by high pressure synthesis. We find that the upper critical field is linearly dependent on temperature near Tc and the…
The interpretation of how superconductivity disappears in cuprates at large hole doping has been controversial. To address this issue, we present an experimental study of single-crystal and thin film samples of La$_{2-x}$Sr$_x$CuO$_4$…