Quasiparticle excitations of molecular chains on graphene

The ability to understand and control the electronic properties of molecular assemblies at the nanoscale is crucial for future technologies. In this talk, we study quasiparticle excitations of linear chains of F4-TCNQ molecules on graphene in a field-effect transistor setup and demonstrate the ability to control their charge state by means of the gate voltage. In particular, we employ ab initio density-functional theory and GW calculations to parametrize a model Hamiltonian which describes the adsorbed molecules as Anderson model impurities interacting via the screened Coulomb interaction. In agreement with recent scanning tunnelling experiments, our calculations predict a range of gate voltages at which every other molecule is occupied by an extra electron.