Signatures of Klein tunneling in disordered graphene p-n-p junctions

We present a method for obtaining quantum transport properties in graphene that uniquely combines three crucial features: microscopic treatment of charge disorder, fully quantum mechanical analysis of transport, and the ability to model experimentally relevant system sizes. As a pertinent application we study the disorder dependence of Klein tunneling dominated transport in p-n-p junctions. Both the resistance and the Fano factor show broad resonance peaks due to the presence of quasi bound states. This feature is washed out by the disorder when the mean free path becomes of the order of the distance between the two p-n interfaces.