Fabrication and properties of arrays of superconducting nanowires

We report on the fabrication and structural characterization of arrays of superconducting nanowires by electroplating lead into the nanopores of track-etched polymer membranes. The diameters of the lead nanowires range from 400 down to 70 nm, whereas their length is about 20 μm. Large enhancement of the critical field has been observed in good agreement with the Ginsburg–Landau–Silin theory. By comparing the predicted critical field enhancement for thin cylinders with experimental results, we have extracted the effective penetration depth. The dependence of the effective penetration depth and electron mean free path on the wire diameter is also discussed.