Making use of focused Ga-ion beam (FIB) fabrication technology, the evolution with device dimension of the low-temperature electrical properties of Nb nanowires has been examined in a regime where crossover from Josephson-like to insulating behaviour is evident. Resistance-temperature data for devices with a physical width of order 100 nm demonstrate suppression of superconductivity, leading to dissipative behaviour that is shown to be consistent with the activation of phase-slip below Tc. This study suggests that by exploiting the Ga-impurity poisoning introduced by the FIB into the periphery of the nanowire, a central superconducting phase-slip nanowire with sub-10 nm dimensions may be engineered within the core of the nanowire.
@article{arxiv.1003.5430,
title = {Superconducting transition in Nb nanowires fabricated using focused ion beam},
author = {G. C. Tettamanzi and C. I. Pakes and A. Potenza and S. Rubanov and C. H. Marrows and S. Prawer},
journal= {arXiv preprint arXiv:1003.5430},
year = {2010}
}