Related papers: c-Axis tunneling in YBa2Cu3O7-\delta/PrBa2Cu3O7-\d…
Superconductivity has recently been discovered in Pr$_{2}$Ba$_{4}$Cu$_{7}$O$_{15-\delta}$ with a maximum $T_c$ of about 15K. Since the CuO planes in this material are believed to be insulating, it has been proposed that the…
Point-contact tunneling on CaC$_6$ crystals reproducibly reveals superconducting gaps, $\Delta$, of 2.3$\pm$0.2 meV which are $\sim$~40% larger than earlier reports. That puts CaC$_6$ into the class of very strong-coupled superconductors…
Superconductivity in thin films and powders, and in single crystals of Pr-123 has been found by Blackstead et al. and Zou et al., respectively. Nevertheless, up to now it has never been reported in sintered-policrystalline samples. We have…
Distinct discontinuities in the thermal expansion of the crystal lattice are observed at the melting-transition of the vortex lattice in a naturally untwinned reversible YBa2Cu3O7-d-single crystal using high-resolution dilatometry. This…
We calculate the c-axis infrared conductivity $\sigma_c(\omega)$ in underdoped cuprate superconductors for spinfluctuation exchange scattering within the CuO$_2$-planes including a phenomenological d-wave pseudogap of amplitude $E_g$. For…
The anisotropic conductivity of thin Nd$_{1.85}$Ce$_{0.15}$CuO$_{4-\delta}$ films was measured in the frequency range 8 cm$^{-1}<\nu <$ 40 cm$^{-1}$ and for temperatures 4 K $<T<300$ K. A tilted sample geometry allowed to extract both,…
Low-temperature (down to $\sim$ 50 mK) thermal conductivity measurements with the heat flow direction along the inter-plane tetragonal $c$-axis, $\kappa_c$, were used to study the superconducting state of heavy fermion CeIrIn$_5$.…
The intermetallic compounds AAl2-xSix, where A = Ca, Sr or Ba, crystallize in the C32 structure, same as the recently discovered MgB2 with a high superconducting transition temperature of 39 K. For x = 1, superconductivity has been observed…
We present an extension of the c-axis tight-binding sum rule discussed by Chakravarty, Kee, and Abrahams [Phys. Rev. Lett. 82, 2366 (1999)] that applies to multilayer high-Tc cuprate superconductors (HTCS) and use it to estimate--from…
A detailed zero-field and transverse-field muon spin relaxation/rotation ($\mu$SR) experiemnts have been carried out on the recently discovered non-centrosymmetric superconductor W$_3$Al$_2$C to speculate about its superconducting ground…
We performed the first scanning tunneling spectroscopy measurements on the pyrochlore superconductor KOs2O6 (Tc = 9.6 K) in both zero magnetic field and the vortex state at several temperatures above 1.95 K. This material presents…
Recent developments in high-temperature superconductivity highlight a generic tendency of the cuprates to develop competing electronic (charge) supermodulations. While coupled to the lattice and showing different characteristics in…
Sub-nanovolt resolution longitudinal and Hall voltages are measured in an ultra pure YBa2Cu3O7-d single crystal. The Hall anomaly and the first-order vortex-lattice melting transition are observed simultaneously. Changes in the dynamic…
A novel interplay between d-wave superconducting order parameter symmetry and the underlying Cu 3d orbital based electronic structure of Copper-Oxides leads to a striking anisotropy in the superfluid response of these systems. In clean…
Using a conventional BCS -- Fermi liquid model we calculate the c-axis optical reflectivity of the layered high temperature cuprate superconductors by obtaining the finite temperature dynamical dielectric function in a microscopic…
In- and out-of-plane London penetration depths were measured in single crystals CaAlSi (T_{c}=6.2 K and 7.3 K) using a tunnel-diode resonator. A full 3D BCS analysis of the superfluid density is consistent with a prolate spheroidal gap,…
Scanning tunneling spectroscopy was performed on single crystals of superconducting 2H-NbSe2, at 300 mK and in a magnetic field, up to 5 T, applied parallel to the ab-plane. This novel field geometry allows the quasiparticle…
Since the discovery of high-temperature superconductivity (SC) in quasi-two-dimensional copper oxides, a few layered compounds, which bear similarities to the cuprates, have also been found to host unconventional SC. Our recent observation…
The temperature and angular dependence of the c-axis Josephson current and the superfluid density in layered d-wave superconductors are studied within the framework of an extended Ambegaokar-Baratoff formalism. In particular, the effects of…
Transition metal dichalcogenides exhibit many unexpected properties including two-dimensional (2D) superconductivity as the interlayer coupling being weakened upon either layer-number reduction or chemical intercalation. Here we report the…