Superconducting Single-Electron Transistor in a Locally Tunable Electromagnetic Environment: Dissipation and Charge Fluctuations

TL;DR

This paper presents a superconducting single-electron transistor system with a tunable electromagnetic environment, demonstrating how dissipation affects conductance and charge fluctuations, with experimental results aligning with theoretical models.

Contribution

We introduce a novel S-SET coupled to a 2DEG with tunable dissipation, providing insights into electromagnetic fluctuations and charge dynamics in such systems.

Findings

Conductance varies nonmonotonically with 2DEG impedance.

Good agreement between experimental data and fluctuation models.

Dissipation influences charge fluctuations and conductance behavior.

Abstract

We have developed a novel system consisting of a superconducting single-electron transistor (S-SET) coupled to a two-dimensional electron gas (2DEG), for which the dissipation can be tuned in the immediate vicinity of the S-SET. Within linear response, the S-SET conductance varies nonmonotonically with increasing 2DEG impedance. We find good agreement between our experimental results and a model incorporating electromagnetic fluctuations in both the S-SET leads and the 2DEG, as well as low-frequency switching of the S-SET offset charge.