Theory of the quantum Hall effect in graphene
  We study the quantum Hall effect (QHE) in graphene based on the current injection model. In our model, the presence of disorder, the edge-state picture, extended states and localized states, which are believed to be indispensable ingredients in describing the QHE, do not play an important role. Instead the boundary conditions during the injection into the graphene sheet, which are enforced by the presence of the Ohmic contacts, determine the current-voltage characteristics. 
Tobias Kramer and Christoph Kreisbeck and Viktor Krueckl and Eric J   Heller and Robert E Parrott and Chi-Te Liang