Tuning the proximity effect in a superconductor-graphene-superconductor junction

TL;DR

This paper demonstrates how in situ tuning of the proximity effect in a graphene-based Josephson junction can be achieved through annealing, enhancing contact quality and inducing supercurrent.

Contribution

It introduces a method to control the proximity effect in graphene Josephson junctions via annealing, improving interface transparency and enabling supercurrent.

Findings

Annealing increases interface transmission coefficient.

Multiple Andreev reflections are enhanced.

Josephson current is successfully induced in graphene.

Abstract

We have tuned in situ the proximity effect in a single graphene layer coupled to two Pt/Ta superconducting electrodes. An annealing current through the device changed the transmission coefficient of the electrode/graphene interface, increasing the probability of multiple Andreev reflections. Repeated annealing steps improved the contact sufficiently for a Josephson current to be induced in graphene.