Superconducting Proximity Effect in Crystalline Co and Cu Nanowires

Superconducting proximity effect is investigated by electrical resistance measurements in individual single-crystal Cu and polycrystalline Co nanowires in contact with a W-based floating inducer electrode (Tc= 5.2 K). Our analysis of the resistance drops shows that in both nanowires,(i)the superconducting proximity length ξ is of the order of 1μm at 2.4 K and (ii) its temperature dependencies can be fitted well to an expression of the form ξ(T)∝√ 1/Tin a wide temperature range, in good agreement with the theoretical predictions for ξ(T )in the diffusive limit. For the Co nanowire, dependencies of the spin-triplet ξ upon current and magnetic field are also reporte