Electronic structure of doped hydrocarbon superconductors

Abstract

We performed electron energy-loss spectroscopy studies in transmission in order to get a deeper insight into the electronic structure of the potassium intercalated recently discovered aromatic hydrocarbon superconductors, such as picene or coronene. A comparison of the loss function of the undoped and doped compound shows the appearance of a new peak in the case of picene and several new peaks in the case of coronene in the optical gap. For picene we find a remarkable negative plasmon dispersion and a dramatic increase for the value of the background dielectric constant upon doping.