title: Evidence of composite plasmon–phonon  modes in the electronic response of  epitaxial graphene.
abstract: The electronic response of quasi-freestanding graphene on Pt(111) has been measured by high-resolution electron energy loss spectroscopy. Loss spectra reveal the existence of three distinct excitations: a dispersing feature due to the ordinary sheet plasmon and two dispersionless modes at 0.2 and 0.5–0.6 eV. The latter two features are assigned to the coupled plasmon–phonon excitation and to an interface plasmon, respectively. The complex interactions of plasmons with other particles have significant fundamental and practical implications on the electronic response of graphene and their knowledge is essential for tailoring upcoming graphene-based plasmonic devices.
authors.affiliation: Dipartimento di Fisica, Università degli Studi della Calabria, I-87036 Rende (Cs), Italy.
authors.forename: A
authors.initials: A
authors.lastname: Politano
authors.forename: V
authors.initials: V
authors.lastname: Formoso
authors.forename: G
authors.initials: G
authors.lastname: Chiarello