Electronic transport in double-nanowire superconducting islands with multiple terminals

TL;DR

This paper investigates the electronic transport properties of a superconducting island formed by parallel nanowires, revealing a gate-tunable sub-gap state that is accessible via multiple terminals and free from quasiparticle poisoning.

Contribution

It introduces a novel parallel nanowire platform with a superconducting island, demonstrating tunable sub-gap states and multi-terminal accessibility for quantum device applications.

Findings

Coulomb blockade peaks indicate a sub-gap state extended over the nanowire island.

The system's properties are tunable by magnetic field, temperature, and gate voltages.

The platform is free of quasiparticle poisoning, enhancing its suitability for quantum technologies.

Abstract

We characterize in-situ grown parallel nanowires bridged by a superconducting island. The magnetic-field and temperature dependence of Coulomb blockade peaks measured across different pairs of nanowire ends are consistent with a sub-gap state extended over the hybrid parallel-nanowire island. Being gate-tunable, accessible by multiple terminals and free of quasiparticle poisoning, these nanowires show promise for the implementation of several proposals that rely on parallel nanowire platforms.