Scaling of the Energy Gap in Pattern-Hydrogenated Graphene

Recent experiments show that a substantial energy gap in graphene can be induced via patterned hydrogenation on an iridium substrate. Here, we show that the energy gap is roughly proportional to N-H(1/2)/N-C when disorder is accounted for, where N-H and N-C denote concentrations of hydrogen and carbon atoms, respectively. The dispersion relation, obtained through calculation of the momentum-energy resolved density of states, is shown to agree with previous angle-resolved photoemission spectroscopy results. Simulations of electronic transport in finite size samples also reveal a similar transport gap, up to 1 eV within experimentally achievable N-H(1/2)/N-C values.