Abstract
The quantum Hall effect is observed in a two-dimensional electron gas formed in millimeter-scale hydrogenated graphene, with a mobility less than and corresponding Ioffe-Regel disorder parameter . In a zero magnetic field and low temperatures, the hydrogenated graphene is insulating with a two-point resistance of the order of . The application of a strong magnetic field generates a negative colossal magnetoresistance, with the two-point resistance saturating within 0.5% of at 45 T. 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.
- Received 7 January 2013
DOI:https://doi.org/10.1103/PhysRevLett.110.176801
© 2013 American Physical Society