Zero-bias conductance peak and Josephson effect in graphene-NbTiN junctions

TL;DR

This paper reports on electronic transport measurements in graphene-NbTiN junctions, revealing a zero-bias conductance peak and Josephson effects, demonstrating robust superconductivity and quantum phenomena in these hybrid devices.

Contribution

It presents the first observation of zero-bias conductance enhancement and Josephson effects in graphene with NbTiN contacts, highlighting the potential for superconducting quantum devices.

Findings

Enhanced conductance at zero bias due to reflectionless tunneling

Observation of Josephson supercurrents in graphene-NbTiN junctions

Fraunhofer patterns indicating quantum interference effects

Abstract

We report electronic transport measurements of graphene contacted by NbTiN electrodes, which at low temperature remain superconducting up to at least 11 Tesla. In devices with a single superconducting contact, we find a more than twofold enhancement of the conductance at zero bias, which we interpret in terms of reflectionless tunneling. In devices with two superconducting contacts, we observe the Josephson effect, bipolar supercurrents and Fraunhofer patterns.