The effect of spin mixing on the quantum Hall effect in graphene.

On the basis of a tight-binding model, we study numerically the effect of Rashba spin-orbit coupling on the quantum Hall effect in graphene. It is found that the spin-orbit coupling can open a gap in the energy spectrum of the counterpropagating edge states in the ν = 0 plateau region, while the edge states in other plateau regions remain gapless. In the presence of disorder, the energy spectrum in the ν = 0 plateau region shows the feature of level repulsion, an indication of switching on of backward scattering and localization of the edge states. This result may explain the insulator-like behavior near the Dirac points observed in experiments at low temperatures.