Premature Switching in Graphene Josephson Transistors

TL;DR

This paper studies how thermal fluctuations cause premature switching in graphene-based Josephson transistors, affecting their critical current and product, and provides a model that aligns with experimental observations.

Contribution

It introduces a comprehensive explanation of premature switching effects in graphene Josephson transistors using the RCSJ model, highlighting the role of thermal fluctuations.

Findings

Suppression of critical current Ic observed experimentally.

Large variation in IcRn product compared to ballistic theory.

Model incorporating premature switching matches experimental data.

Abstract

We investigate electronic transport in single layer graphene coupled to superconducting electrodes. In these Josephson transistors, we observe significant suppression in the critical current Ic and large variation in the product IcRn in comparison to theoretic predictions in the ballistic limit. We show that the depression of Ic can be explained by premature switching in underdamped Josephson junctions described within the resistively and capacitively shunted junction (RCSJ) model. By considering the effect of premature switching and dissipation, the calculated gate dependence of product IcRn agrees with experimental data. Our discovery underscores the crucial role of thermal fluctuations in electronic transport in graphene Josephson transistors.