Proximity Induced Josephson-Quasiparticle Process in a Single Electron Transistor

TL;DR

This paper reports the first experimental observation of proximity-induced Josephson-quasiparticle processes in a superconductor-normal metal-superconductor single electron transistor, revealing new insights into proximity effects and quasiparticle dynamics.

Contribution

It introduces the first experimental demonstration of proximity-induced Josephson-quasiparticle processes in a single electron transistor with a superconducting proximity effect.

Findings

Observation of current peaks below quasiparticle threshold

Identification of Josephson-quasiparticle process as the origin of these peaks

Discussion of the proximity-induced energy gap in the normal metal

Abstract

We have performed the first experiments in a superconductor - normal metal - superconductor single electron transistor in which there is an extra superconducting strip partially overlapping the normal metal island in good metal-to-metal contact. Superconducting proximity effect gives rise to current peaks at voltages below the quasiparticle threshold. We interpret these peaks in terms of the Josephson-quasiparticle process and discuss their connection with the proximity induced energy gap in the normal metal island.