Quantum Hall effect in hydrogenated graphene

J. Guillemette, S. S. Sabri, B. Wu, K. Bennaceur, P. E. Gaskell, M. Savard, P. L. Lévesque, F. Mahvash, A. Guermoune, M. Siaj, R. Martel, T. Szkopek, and G. Gervais

Accepted Friday Mar 8, 2013

The quantum Hall effect is observed in a two-dimensional electron gas formed in millimeter-scale hydrogenated graphene, with a mobility less than 10 cm2/V·s and corresponding Ioffe-Regel disorder parameter (kFl)-1 >> 1. In zero magnetic field and low temperatures, the hydrogenated graphene is insulating with a two-point resistance of order of 250 h/e2. Application of a strong magnetic field generates a negative colossal magnetoresistance, with the two-point resistance saturating within 0.5% of h/2e2 at 45T. Our observations are consistent with the opening of an impurity-induced gap in the density of states of graphene. The interplay between electron localization by defect scattering and magnetic confinement in two-dimensional atomic crystals is discussed.