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 (oddmembered 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.