Effect of potential disorder on the shot noise properties of graphene ribbons

We use an envelope-function based simulation code to study the shot noise properties of graphene ribbons. Tworzydło et al. [1] predicted a peculiar behavior, as a function of the chemical potential or of the voltage applied to a backgate, for graphene samples with a large aspect ratio. A few experiments have been performed to validate such a prediction. On the basis of our simulations for ribbons with a realistic size, we conclude that the experimental results published until now are the result of the presence of disorder, rather than of the effect predicted by Tworzydło et al.. Therefore, further work is needed to achieve an experimental observation of such a behavior. Our numerical results show that this should indeed be possible considering suspended graphene ribbons, with a sufficiently small voltage applied between the electrodes, and operating at very low temperature.