Related papers: The c-axis optical sum rule and possible new colle…

We report the reflectivity and the resistivity measurement of Ca_{2-x}Na_{x}CuO_{2}Cl_{2} (CNCOC), which has a single-CuO2-plane lattice with no orthorhombic distortion. The doping dependence of the in-plane optical conductivity spectra for…

We measured the temperature dependence of the in-plane polarized reflectivity spectra of twin-free Y$_{1-x}$Ca$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-{\delta}}$ single crystals with different Ca-concentrations (x=0,0.11 and 0.16) from optimally doped…

We report the observation of coherent oscillations associated with charge density wave (CDW) order in the underdoped cuprate superconductor YBa2Cu3O6+x by time-resolved optical reflectivity. Oscillations with frequency 1.87 THz onset at…

The optimally doped and underdoped region of the $t-J$ model at large N (N is the number of spin components) is governed by the competition of d-wave superconductivity (SC) and a d Charge-Density Wave (d-CDW).The partial destruction of the…

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)…

The superconducting properties of a recently proposed phenomenological model for a weakly doped antiferromagnet are analyzed, taking into account fluctuations of the phase of the order parameter. In this model, we assume that the doped…

The cuprate superconductors display several characteristic temperatures which decrease as the material composition is doped, tracing lines across the temperature-doping phase diagram. Foremost among these is the pseudogap transition. At a…

New break-junction tunneling data are reported in Bi2Sr2CaCu2O(8+delta) over a wide range of hole concentration from underdoped (Tc = 74 K) to optimal doped (Tc = 95 K) to overdoped (Tc = 48 K). The conductances exhibit sharp dips at a…

We determined the optical conductivity of Bi(2)Sr(2-x)La(x)CuO(6) at dopings covering the phase diagram from the underdoped to the overdoped regimes. The frequency dependent scattering rate shows a pseudogap extending into the overdoped…

We report a density-matrix renormalization group study of the lightly doped $t$-$J$ model on a 4-leg cylinder with doped hole concentrations per site $\delta=5\%\sim 12.5\%$. By keeping an unusually large number of states and long system…

The effect of off-plane impurity on superconductivity and non-Fermi-liquid (NFL) behavior in the layered heavy-fermion compound CeCo$_{1-x}$Ni$_x$In$_5$ is investigated by specific heat, magnetization, and electrical resistivity…

We show that a multilayer analysis of the infrared c-axis response of RBa2Cu3O7-d (R=Y, Gd, Eu) provides important new information about the anomalous normal state properties of underdoped cuprate high temperature superconductors. Besides…

Two critical points have been revealed in the normal-state phase diagram of the electron-doped cuprate superconductor Nd$_{2-x}$Ce$_x$CuO$_4$ by exploring the Fermi surface properties of high quality single crystals by high-field…

Andreev-reflection and tunneling studies have been carried out on a single crystal of underdoped Nd1.85Ce0.15CuO4-d (NCCO) by using Ag, Pt-Ir and Nb tips to clarify the symmetry of its order parameter. Surprisingly, we observed in the NCCO,…

We measured the optical reflectivity of [001]-oriented $n$-doped Cd$_{3}$As$_{2}$ in a broad frequency range (50 - 22000 cm$^{-1}$) for temperatures from 10 to 300 K. The optical conductivity, $\sigma(\omega) = \sigma_{1}(\omega) + {\rm…

Here we report the synthesis and basic characterization of SmFe1-xCoxAsO (x=0.10, 0.15). The parent compound SmFeAsO itself is not superconducting but shows an antiferromagnetic order near 150 K, which must be suppressed by doping before…

Optical reflectivity experiments have been conducted on single crystals of the Kondo insulator YbB_12 in order to obtain its optical conductivity, \sigma(\omega). Upon cooling below 70 K, a strong supression of \sigma(\omega) is seen in the…

We discuss the problem of a possible "violation" of the optical sum rule in the normal (non superconducting) state of strongly correlated electronic systems, using our recently proposed DMFT+Sigma approach, applied to two typical models:…

Recent observation of the light-induced superconducting (SC)-like transient response in the $c$-axis optical conductivity far above the SC transition temperature $T_{\mathrm{c}}$ in underdoped YBa$_2$Cu$_3$O$_y$ (YBCO) has attracted great…

An optical "pseudogap" is usually assumed to open at low T in the "anomalous Drude" absorption, which models the optical conductivity sigma(omega) (proportional to omega-1) of HCTS by a linewidth Gamma (on the order of 1000 cm-1) varying…