Related papers: Rapid change of electronic anisotropy in overdoped…
In order to access the overdoped regime of the YBa_2Cu_3O_y phase diagram, 2% Ca is substituted for Y in YBa_2Cu_3O_y (y = 7.00,6.93,6.88,6.76). Raman scattering studies have been carried out on these four single crystals. Measurements of…
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…
We investigated the effects of $c/a$ anisotropy and local crystal structure on superconductivity (SC) in As/P solid solution systems, $A\mathrm{Fe_{2}}(\mathrm{As}_{1-x}\mathrm{P}_{x}\mathrm{)_{2}}$ ($A$122P) with various $A$ ions. With…
We present results of Raman scattering experiments on tetragonal ${\rm (Y_{1-y}Ca_{y})Ba_{2}Cu_{3}O_{6+x}}$ for doping levels $p(x,y)$ between 0 and 0.07 holes/CuO$_2$. Below the onset of superconductivity at $p_{\rm sc1} \approx 0.06$, we…
The ab-plane reflectance of Bi2Sr2CaCu2O(8+d) thin films was measured in the 30-25000 cm^(-1) range for one underdoped (Tc = 70 K), and one overdoped sample (Tc = 63 K) as a function of temperature (10-300 K). We find qualitatively similar…
We investigated the in-plane anisotropy on the resistivity and thermopower of Bi2-xPbxSr2Co2Oy single crystals, which have a misfit structure between the hexagonal CoO2 layer and the rock salt Bi2Sr2O4 layer. The resistivity and thermopower…
We have carried out a comprehensive high-resolution angle-resolved photoemission spectroscopy (ARPES) study of the pseudogap interplay with superconductivity in La-based cuprates. The three systems La$_{2-x}$Sr$_x$CuO$_4$,…
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…
We have investigated the superconducting(SC)-gap anisotropy for several Ba-doped KFe$_2$As$_2$ samples using laser-based angle-resolved photoemission spectroscopy. We show that the SC-gap anisotropy and node positions drastically change…
We investigate the manifestation of the stripes in the in-plane resistivity anisotropy in untwinned single crystals of La_{2-x}Sr_{x}CuO_{4} (x = 0.02 - 0.04) and YBa_{2}Cu_{3}O_{y} (y = 6.35 - 7.0). It is found that both systems show…
A systamatic quantitative comparison of ''pseudogap'' values obtained from the analysis of charge and spin excitation spectroscopies in underdoped YBa2Cu3O7-x using a temperature-independent gap shows two distinct excitations, one visible…
The impact of the normal-state pseudogap, present in all optimal and underdoped HTS cuprates, on critical currents and critical temperature is surveyed. With the opening of the pseudogap around a doping state of p=0.19 the condensation…
The dependence of the superconducting gaps in epitaxial Ba(Fe_{1-x}Co_{x})_2As_2 thin films on the nominal doping x (0.04 \leq x \leq 0.15) was studied by means of point-contact Andreev-reflection spectroscopy. The normalized conductance…
We measured the in-plane resistivity anisotropy in the underdoped Ca$_{1-x}$Na$_x$Fe$_2$As$_2$ single crystals. The anisotropy (indicated by $\rho_{\rm b} - \rho_{\rm a}$) appears below a temperature well above magnetic transition…
The doping dependence of the themopower, in-plane resistivity rho_ab(T), out-of-plane resistivity rho_c(T), and susceptibility has been systematically measured for high-quality single crystal Bi2Sr2Ca2Cu3O10+delta. We found that the…
A reduction of the density of states near the Fermi energy in the normal state (pseudogap) of high-temperature oxide superconductors is examined on the basis of the two-dimensional tight-binding model with effective interactions due to…
The electron paramagnetic resonance is used to measure the single-ion anisotropy of Gd3+ ions in the pyrochlore structure of (Y{1-x}Gdx)2Ti2O7. A rather strong easy-plane type anisotropy is found. The anisotropy constant D is comparable to…
We investigated the in-plane resistivity anisotropy for underdoped Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ single crystals with improved quality. We demonstrate that the anisotropy in resistivity in the magnetostructural ordered phase arises from…
The momentum dependence of the superconducting gap in the cuprates has been debated, with most experiments reporting a deviation from a simple $d_{x^2-y^2}$ form in the underdoped regime and a few experiments claiming that a simple…
The influence of low-level Pr substitution in Y1-xPrxBa2Cu3O(7-delta) single crystals on the anisotropy of the superconducting state parameters was investigated by torque magnetometry in magnetic fields of up to 9 T. An averaged anisotropy…