Quantum transport at the Dirac point and Klein tunneling in disordered graphene

We describe a robust method to obtain transport properties at the Dirac point in disordered graphene that uniquely combines three crucial features: 1) fully quantum mechanical calculation of transport properties using the transfer matrix approach, 2) a microscopic treatment of the effects of charged disorder with the self-consistent Thomas-Fermi-Dirac density functional method, and 3) the ability to treat experimentally relevant system sizes. As an application we discuss the effects of disorder on Klein tunneling in p-n-p junctions.