Effect of dilute impurities on short graphene Josephson junctions

TL;DR

This paper investigates how dilute non-magnetic impurities affect the supercurrent in short graphene Josephson junctions, revealing modifications to the current-phase relation and potential for spectroscopic analysis of Andreev bound states.

Contribution

It introduces a theoretical framework using the Dirac-Bogoliubov-de Gennes approach to model impurity effects on supercurrent in graphene Josephson junctions, highlighting new spectral insights.

Findings

Impurity presence reduces current-phase relation skewness.

Critical current exhibits nonmonotonic temperature dependence.

Supercurrent power spectrum enables spectroscopy of Andreev bound states.

Abstract

We study the effect of a dilute homogeneous spatial distribution of non-magnetic impurities on the equilibrium supercurrent sustained by a ballistic graphene Josephson junction in the short junction limit. Within the Dirac-Bogoliubov-de Gennes approach and modeling impurities by the Anderson model we derive the supercurrent and its equilibrium power spectrum. We find a modification of the current-phase relation with a reduction of the skewness induced by disorder, and a nonmonotonic temperature dependence of the critical current. The potentialities of the supercurrent power spectrum for accurate spectroscopy of the hybridized Andreev bound states-impurities spectrum are highlighted. In the low temperature limit, the supercurrent zero frequency thermal noise directly probes the spectral function at the Fermi energy.