title: Plasmon modes of a silver thin film taper probed with STEM-EELS.
abstract: By focusing propagating surface plasmons, electromagnetic energy can be delivered to nanoscale volumes. In this context, we employ electron energy loss spectroscopy in a scanning transmission electron microscope to characterize the full plasmonic mode spectrum of a silver thin film tapered to a sharp tip. We show that the plasmon modes can be ordered in film and edge modes and corroborate our assignment through supplementary numerical simulations. In particular, we find that the focused plasmon field at the taper tip is fueled by edge modes.
authors.forename: Franz-Philipp
authors.initials: FP
authors.lastname: Schmidt
authors.forename: Harald
authors.initials: H
authors.lastname: Ditlbacher
authors.forename: Andreas
authors.initials: A
authors.lastname: Trügler
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hohenester
authors.forename: Andreas
authors.initials: A
authors.lastname: Hohenau
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Hofer
authors.forename: Joachim R
authors.initials: JR
authors.lastname: Krenn