Shot Noise in Graphene

L. DiCarlo, J. R. Williams, Yiming Zhang, D. T. McClure, C. M. Marcus

Published 2007-11-20, updated 2008-02-21Version 3

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.