Work

Local Control of Parity and Charge in Nanoscale Superconducting Lead Islands

Year: 2025

Type: article

Abstract: Small superconducting islands can exhibit charge quantization, where Coulomb interactions compete with Cooper pairing. Using scanning tunneling spectroscopy, we probe this interplay by measuring the charging energy (E_{C}) and the pairing energy (Δ) of individual Pb nanoislands. Below a critical island size, where E_{C}>Δ, we observe a crossover between even and odd parity ground states. By applying controlled voltage pulses, we continuously tune the island's electrostatic potential and map the full charge-parity landscape. These results demonstrate tunable superconducting ground states, offering a potential platform for qubit design and control.

Source: Physical Review Letters

DOI: 10.1103/vkwr-m87v

Authors: Stefano Trivini, Jon Ortuzar, Katerina Vaxevani, Beatriz Viña-Bausá, F. Sebastian Bergeret, Jose Ignacio Pascual