title: Photoexcitation of a volume plasmon in C60 ions.
abstract: Neutral C60 is well known to exhibit a giant resonance in its photon absorption spectrum near 20 eV. This is associated with a surface plasmon, where delocalized electrons oscillate as a whole relative to the ionic cage. Absolute photoionization cross-section measurements for C+60, C2+60, and C3+60 ions in the 17-75 eV energy range show an additional resonance near 40 eV. Time-dependent density functional calculations confirm the collective nature of this feature, which is characterized as a dipole-excited volume plasmon made possible by the special fullerene geometry.
authors.affiliation: Department of Physics, MS 220, University of Nevada, Reno, Nevada 89557-0058, USA.
authors.forename: S W J
authors.initials: SW
authors.lastname: Scully
authors.forename: E D
authors.initials: ED
authors.lastname: Emmons
authors.forename: M F
authors.initials: MF
authors.lastname: Gharaibeh
authors.forename: R A
authors.initials: RA
authors.lastname: Phaneuf
authors.forename: A L D
authors.initials: AL
authors.lastname: Kilcoyne
authors.forename: A S
authors.initials: AS
authors.lastname: Schlachter
authors.forename: S
authors.initials: S
authors.lastname: Schippers
authors.forename: A
authors.initials: A
authors.lastname: Müller
authors.forename: H S
authors.initials: HS
authors.lastname: Chakraborty
authors.forename: M E
authors.initials: ME
authors.lastname: Madjet
authors.forename: J M
authors.initials: JM
authors.lastname: Rost