Electronic signatures of topological disorder in amorphous graphene

There have been extensive studies of the many phases of carbon, involving diamond and graphite, fullerenes, carbon nanotubes, amorphous carbon [ 1–3] and Schwarzites. In this study, the authors explore the impact of topological disorder (odd-membered rings) on the electron localisation of amorphous graphene. The authors employ realistic structural models, and find that the electronic states around Fermi level are highly localised around odd-membered rings. They predict an scanning tunnelling microscopic image for the amorphous surface. The authors’ results also suggest that for two-dimensional system, there exist highly localised states well above the Fermi energy not at a band edge, which is rare in three-dimensional system. Phonon calculations reveal that certain atoms in the network are involved in both localised electronic and localised vibrational states, leading us to expect a large electron–phonon coupling between these, which might have interesting observable consequences.