Fabrication of Quasi-One-Dimensional Superconducting Micro- and Nanostructures

Wires capable of conducting electric current are basic blocks of all electronic applications. Of particular interest for nanoelectronics are superconducting elements taking advantage of the superconductor's macroscopic quantum coherence and zero resistance. Recently there appeared indications that due to quantum fluctuations the dissipationless electric current (supercurrent) can be suppressed in ultra-narrow superconducting channels with the effective diameter below ∼ 10 nm. In this Review we will describe methods of fabrication of quasi-one-dimensional superconducting micro- and nanowires suitable for electric transport measurements at cryogenic temperatures. In the first section we will concentrate on structures with characteristic cross-section ∼ 1 μm, while in the second section we will focus on much narrower systems down to sub-10 nm scales.