The electrical conductivity of bundles of superconducting nanowires produced by laser ablation of metals in superfluid helium

The temperature dependencies of the electrical resistance are reported for bundles of permalloy, indium, tin, and lead nanowires having a similar diameter of about 8 rim which were grown by catalytic coagulation of laser ablation products in quantized vortices of superfluid helium. In all metals, the constant residual resistance found at low temperatures changes to a superlinear growth at higher temperatures. For all superconducting nanowires, the transition to superconductivity is broadened with a width of delta T = 0.6K. The size shift of the transition center AT is largest for lead, Delta T = 2 K, whereas for indium and tin AT is 0.2 K and <0.1 K, respectively. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4742330]