  Superconducting nanowires can be fabricated by decomposition of an
organometallic gas using a focused beam of Ga ions. However, physical damage
and unintentional doping often results from the exposure to the ion beam,
motivating the search for a means to achieve similar structures with a beam of
electrons instead of ions. This has so far remained an experimental challenge.
We report the fabrication of superconducting tungsten nanowires by
electron-beam-induced-deposition, with critical temperature of 2.0 K and
critical magnetic field of 3.7 T, and compare them with superconducting wires
made with ions. This work opens up new possibilities for the realization of
nanoscale superconducting devices, without the requirement of an ion beam
column.
