Shot Noise in Graphene

Abstract

We report measurements of current noise in single-layer and multilayer graphene devices. In four single-layer devices, including a $p\mathrm{\text{−}}n$ junction, the Fano factor remains constant to within $\pm 10\%$ upon varying carrier type and density, and averages between 0.35 and 0.38. The Fano factor in a multilayer 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 theories for shot noise in ballistic and disordered graphene.