Single-crystal superconducting nanowires of NbSe₂ fabricated by reactive plasma etching

We present the preparation and measurements of nanowires of single-crystal NbSe₂. These nanowires were prepared on ultrathin (a10nm) flakes of NbSe₂ mechanically exfoliated from a bulk single crystal using a process combining electron beam lithography and reactive plasma etching. The electrical contacts to the nanowires were prepared using Ti/Au. Our technique, which overcomes several limitations of methods developed previously for fabricating superconducting nanowires, also allows for the preparation of complex superconducting nanostructures with a desired geometry. Current-voltage characteristics of individual superconducting single-crystal nanowires with widths down to 30nm and cross-sectional areas as low as 270 nm² were measured.