Quantum Hall conductance of two-terminal graphene devices

Measurement and theory of the two-terminal conductance of monolayer and bilayer graphene in the quantum Hall regime are compared. We examine features of conductance as a function of gate voltage that allow monolayer, bilayer, and gapped samples to be distinguished. In particular, we analyze the distortions of quantum Hall plateaus and the conductance peaks and dips at the charge-neutrality point, which can be used to identify the incompressible densities. These results are compared to recent theory and possible origins of the discrepancy are discussed.