Niobium thin film wires were fabricated using electron beam lithography with a four layer liftoff mask system, and subsequently thinned by anodisation. The resistance along the wire was monitored in situ and trimmed by controlling the anodisation voltage. Depending on the room temperature sheet resistance, samples showed either superconducting or insulating behaviour at low temperatures. A Coulomb blockade was observed for samples exceeding 6 kOhm per square. Samples were also made in a single electron transistor-like geometry with two weak links made by combined angular evaporation and anodisation. Their current-voltage characteristics could be modulated by a voltage applied to an overlapping gate.
@article{arxiv.cond-mat/9706302,
title = {Coulomb blockade effects in anodised niobium nanostructures},
author = {Torsten Henning and D. B. Haviland and P. Delsing},
journal= {arXiv preprint arXiv:cond-mat/9706302},
year = {2009}
}
Comments
15 pages, 10 EPS figures, LaTeX2e, to be published in Supercond. Sci. and Technol