Shot Noise in Graphene

TL;DR

This paper presents measurements of shot noise in graphene devices, revealing a nearly constant Fano factor in single-layer graphene and a decreasing trend in multi-layer graphene, providing insights into charge transport properties.

Contribution

It provides experimental data on shot noise in graphene, comparing single- and multi-layer devices, and tests theoretical models of noise in ballistic and disordered regimes.

Findings

Fano factor in single-layer graphene is approximately 0.36, stable across carrier types and densities.

Multi-layer graphene shows a decreasing Fano factor from 0.33 to 0.25 with increasing carrier density.

Results align with theoretical predictions for shot noise in different graphene transport regimes.

Abstract

We report measurements of current noise in single- and multi-layer graphene devices. In four single-layer devices, including a p-n junction, the Fano factor remains constant to within +/-10% upon varying carrier type and density, and averages between 0.35 and 0.38. The Fano factor in a multi-layer device is found to decrease from a maximal value of 0.33 at the charge-neutrality point to 0.25 at high carrier density. These results are compared to theoretical predictions for shot noise in ballistic and disordered graphene.