Plasmon dispersion in quasi-freestanding graphene on Ni(111)

Abstract

The electronic properties of graphene formed on Ni(111) by chemical vapor deposition and intercalated with Cs atoms have been studied by angle-resolved electron-energy-loss spectroscopy. The dispersion curve of π plasmon, in comparison with the analogous dispersion curve obtained in the absence of intercalated Cs, shows that alkali metal atoms make graphene to be quasi-free, with a much lowered charge transfer, and with the recovery of the π band linearity at Dirac points.