title: Nonlocal screening of plasmons in graphene by semiconducting and metallic substrates: first-principles calculations.
abstract: We investigate the role of substrates on the collective excitations of graphene by using a first-principles implementation of the density response function within the random-phase approximation. Specifically, we consider graphene adsorbed on SiC(0001) and Al(111) as representative examples of a semiconducting and metallic substrate. On SiC(0001), the long wavelength π plasmons are significantly damped although their energies remain almost unaltered. On Al(111), the long wavelength π plasmons are completely quenched due to the coupling to the metal surface plasmon. The strong damping of the plasmon excitations occurs despite the fact that the single-particle band structure of graphene is completely unaffected by the substrates illustrating the nonlocal nature of the effect.
authors.affiliation: Center for Atomic-scale Materials Design, Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark.
authors.forename: Jun
authors.initials: J
authors.lastname: Yan
authors.forename: Kristian S
authors.initials: KS
authors.lastname: Thygesen
authors.forename: Karsten W
authors.initials: KW
authors.lastname: Jacobsen