We experimentally investigate supercurrent through Coulomb islands, where island and leads are fabricated from semiconducting nanowires with fully surrounding superconducting shells. Applying flux along the wire yields a series of destructive Little-Parks lobes with reentrant supercurrent. We find Coulomb blockade with 2e peak spacing in the zeroth lobe and 1e average spacing, with regions of significant even-odd modulation, in the first lobe. Evolution of Coulomb-peak amplitude through the first lobe is consistent with a theoretical model of supercurrent carried predominantly by zero-energy states in the leads and the island.
Cite
@article{arxiv.2308.10006,
title = {Supercurrent transport through 1$e$-periodic full-shell Coulomb islands},
author = {D. Razmadze and R. Seoane Souto and E. C. T. O'Farrell and P. Krogstrup and M. Leijnse and C. M. Marcus and S. Vaitiekėnas},
journal= {arXiv preprint arXiv:2308.10006},
year = {2025}
}