Magnetoresistance and magnetic ordering fingerprints in hydrogenated graphene

Spin-dependent features in the conductivity of graphene, chemically modified by a random distribution of hydrogen adatoms, are explored theoretically. The spin effects are taken into account using a mean-field self-consistent Hubbard model derived from first-principles calculations. A Kubo transport methodology is used to compute the spin-dependent transport fingerprints of weakly hydrogenated graphene-based systems with realistic sizes. Conductivity responses are obtained for paramagnetic, antiferromagnetic, or ferromagnetic macroscopic states, constructed from the mean-field solutions obtained for small graphene supercells. Magnetoresistance signals up to ~7% are calculated for hydrogen densities around 0.25%. These theoretical results could serve as guidance for experimental observation of induced magnetism in grapheneSpanish Grants from MICINN to D. S. and J. J. P. (FIS2010-21883-C02-02, CSD2007-00010) and P. O. (FIS2009-12721-C04-01, CSD2007-00050) are acknowledged. D. S. acknowledges the Universidad de Alicante, a CSIC PhD Grant, and J. Fernández-Rossier. This work is connected to the Belgian Program on Interuniversity Attraction Poles (PAI6), the ARC on ‘‘Graphene, ’’ the ETSF e-I3 project (Grant No. 211956) and the Belgium FNR