Imprint of transition metal d-orbitals on graphene Dirac cone

Abstract

We investigate the influence of SiO2, Au, Ag, Cu, and Pt substrates on the Raman spectrum of graphene. Experiments reveal particularly strong modifications to the intensity, position, width, and shape of the Raman signal of graphene on platinum, compared to that of suspended graphene. The modifications strongly depend on the relative orientation of the graphene and platinum lattices. These observations are theoretically investigated and shown to originate from hybridization of electronic states in graphene and d-orbitals in platinum. It is expected that, quite generally, hybridization between graphene and any material with d-orbitals near the Fermi level will result in an imprint on the graphene Dirac cone which depends sensitively on the relative orientation of the respective lattices.