We have measured the critical current as a function of magnetic field in short and narrow superconducting aluminum nanowires. In the range of magnetic fields in which vortices can enter a nanowire in a single row, we find regular oscillations of the critical current as a function of magnetic field. The oscillations are found to correspond to adding a single vortex to the nanowire, with the number of vortices on the nanowire staying constant within each period of the oscillation. This effect can be thought of as a Weber blockade, and the nanowires act as quantum dots for vortices, analogous to the Coulomb blockade for electrons in quantum dots.
@article{arxiv.1406.6802,
title = {Weber blockade in superconducting nanowires},
author = {Tyler Morgan-Wall and Benjamin Leith and Nikolaus Hartman and Atikur Rahman and Nina Markovic},
journal= {arXiv preprint arXiv:1406.6802},
year = {2015}
}