title: Polarized plasmonic enhancement by Au nanostructures probed through Raman scattering of suspended graphene.
abstract: We characterize plasmonic enhancement in a hotspot between two Au nanodisks using Raman scattering of graphene. Single layer graphene is suspended across the dimer cavity and provides an ideal two-dimensional test material for the local near-field distribution. We detect a Raman enhancement of the order of 10(3) originating from the cavity. Spatially resolved Raman measurements reveal a near-field localization one order of magnitude smaller than the wavelength of the excitation, which can be turned off by rotating the polarization of the excitation. The suspended graphene is under tensile strain. The resulting phonon mode softening allows for a clear identification of the enhanced signal compared to unperturbed graphene.
authors.affiliation: Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany. sebastian.heeg@physik.fu-berlin.de
authors.forename: Sebastian
authors.initials: S
authors.lastname: Heeg
authors.forename: Roberto
authors.initials: R
authors.lastname: Fernandez-Garcia
authors.forename: Antonios
authors.initials: A
authors.lastname: Oikonomou
authors.forename: Fred
authors.initials: F
authors.lastname: Schedin
authors.forename: Rohit
authors.initials: R
authors.lastname: Narula
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Maier
authors.forename: Aravind
authors.initials: A
authors.lastname: Vijayaraghavan
authors.forename: Stephanie
authors.initials: S
authors.lastname: Reich