Effects of the contacts on shot noise in graphene nano-ribbons

TL;DR

This paper studies how contacts influence shot noise in graphene nanoribbons, explaining discrepancies between theoretical predictions and experimental results by considering contact effects.

Contribution

It introduces the impact of contacts on shot noise behavior in graphene nanoribbons, providing a more accurate theoretical-experimental comparison.

Findings

Shot noise exhibits universal characteristics at the Dirac point.

Shot noise decreases sharply with increasing carrier density.

Including contact effects explains the smaller experimental slope.

Abstract

We investigate the shot noise of an impurity-free graphene flake as a function of the chemical potential. For large width to length ratios, this noise has been predicted and observed to exhibit universal characteristics at the Dirac point. Furthermore, a sharp decrease of the shot noise with increasing carrier density has been predicted. This decrease has also been observed in experiments, but with much smaller slope than predicted. We reconcile this discrepancy between theory and experiment by including the effects of the contacts to the graphene ribbon.