As the dimensions of thin superconducting structures become comparable with or less than the penetration length of magnetic flux into the structures, it becomes increasingly necessary to devise experimental tests of available theoretical models. One approach which we shall describe, enables penetration lengths to be derived from the measurement of the effective area of planar, thin-film structu...

The deleterious effects of disorder are amplified in lower dimensions, where long-range coherence is, at best, only marginally stable. A case in point is the destruction of superconductivity in ultrathin granular' and continuous metal films. The disorder is parametrized by the film sheet resistance and the data suggest a zero-temperature threshold for quenching global superconducting coherence ...

Tunneling and optical transmission studies have been performed on superconducting samples of Rb3C60. At temperatures much below the superconducting transition temperature Tc, the energy gap is 2D ­ 5.2 6 0.2 meV, corresponding to 2DykBTc ­ 4.2. The low temperature density of states and the temperature dependence of the optical conductivity resemble BCS behavior, although there is an enhanced “n...

We study magneto-transport properties of several amorphous Indium oxide nanowires of different widths. The wires show superconducting transition at zero magnetic field, but, there exist a finite resistance at the lowest temperature. The R(T) broadening was explained by available phase slip models. At low field, and far below the superconducting critical temperature, the wires with diameter equa...

High-quality single crystals of Lu2Fe3Si5 and Sc2Fe3Si5 are grown by the floatingzone method, and their temperature dependences of specific heat are measured down to 0.35 K. Both compounds show anomalously small jump in specific heat at the superconducting transition temperature, Tc, and large residual specific heat coefficient even at 0.2Tc, where BCS superconductor shows negligible electronic...

As the normal state sheet resistance, Rn, of a thin film superconductor increases, its superconducting properties degrade. For Rn ≃ h/4e superconductivity disappears and a transition to a nonsuperconducting state occurs. We present electron tunneling and transport measurements on ultrathin, homogeneously disordered superconducting films in the vicinity of this transition. The data provide stron...

We present local tunneling spectroscopy experiments in the superconducting and ferromagnetic phases of the reentrant superconductor ErRh4B4. The tunneling conductance curves jump from showing normal to superconducting features within a few mK close to the ferromagnetic transition temperature, with a clear hysteretic behavior. Within the ferromagnetic phase, we do not detect any superconducting ...