This paper describes development and initial results for a small prototype superconducting undulator with a period less than 1 cm, referred to here as a “supermini” undulator. The development of superconducting mini-undulators started in the early 1990s with work at BNL and KIT (Germany). In 1998, KIT demonstrated the first photon production with a super-mini of 3.8 mm period length [1]. This s...

We report on electrical transport measurements in a carbon nanotube quantum dot coupled to a normal and a superconducting lead. Depending on the ratio of Kondo temperature T K and superconducting gap ∆ the zero bias conductance resonance either is split into two side-peaks or persists. We also compare our data with a simple model of a resonant level-superconductor interface. At low temperatures...

We investigate the electronic and superconducting properties of a negative-U Hubbard model. For this purpose we evaluate a recently introduced variational theory based on Gutzwiller-correlated BCS wavefunctions. We find significant differences between our approach and standard BCS theory, especially for the superconducting gap. For small values of |U|, we derive analytical expressions for the o...

A microscopic model for describing a superconducting mesoscopic weak link is presented. We consider a model geometry consisting of a narrow channel coupled to wider superconducting electrodes which act as reservoirs fixing the asymptotic values of the complex order parameter. For this model, the Bogoliubov-de Gennes equations are discretized and solved self-consistently using a non-equilibrium ...

Doping and disorder are inseparable in the superconducting cuprates. Assuming the simplest possible disordered doping, we construct a semiphenomenological model and analyze its experimental consequences. Among the affected experimental quantities are the ARPES spectra and thermodynamic properties. From our model we make a prediction for the width of the local superconducting gap distribution wi...

24 ISSN:1369 7021 © Elsevier Science Ltd 2002 Conventional superconductors Bardeen-Cooper-Schrieffer (BCS) theory provides a microscopic picture of how attractive electron-electron interactions in the degenerate electron gas of a metal result in the formation of Cooper-pairs1. Each Cooper-pair can be considered a bound state of two electrons with opposite spin and momentum. The superconducting ...

The power-law temperature dependences of the specific heat, the nuclear relaxation rate, and the thermal conductivity suggest the presence of line nodes in the superconducting gap of Sr2RuO4. These recent experimental observations contradict the scenario of a nodeless (k(x)+ik(y))-type superconducting order parameter. We propose that interaction of superconducting order parameters on different ...