Multiple Auger processes in Graphene

Resonant Auger decay processes have been studied by resonant photoemission spectroscopy (resPES) and X-ray absorption spectroscopy (XAS) in Graphene systems. The π*-resonance is used to identify the degree of localization of the lowest π*-orbitals in the conduction band. Localization and lifetime of the photo-excited intermediate state cause the formation of multiple Auger processes. For the Graphene systems we identify two novel Auger decay combinations with a four hole final state: the (S + S) and the (S + S)* decay. We demonstrate that these processes are sensitive for interlayer coupling and interactions with the metallic free electrons of the substrate.