title: Electromagnetic interactions in plasmonic nanoparticle arrays.
abstract: Single two-dimensional planar silver arrays and one-dimensional linear gold chains of nanoparticles were investigated by dark-field surface plasmon spectroscopy and studied as a function of interparticle distance, particle size, and number of particles. In agreement with recent theoretical predictions, a red shift of the surface plasmon resonance occurring in two-dimensional arrays was found for lattice spacings below 200 nm. This red shift is associated with a significant broadening of the resonance and is attributed to the onset of near-field interactions. We found that the relative contributions of the long-range and short-range interactions in two-dimensional arrays of particles are fundamentally different to those occurring in individual linear chains.
authors.affiliation: Chemistry Division and Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Bouhelier
authors.forename: Renaud
authors.initials: R
authors.lastname: Bachelot
authors.forename: Jin Seo
authors.initials: JS
authors.lastname: Im
authors.forename: Gary P
authors.initials: GP
authors.lastname: Wiederrecht
authors.forename: Gilles
authors.initials: G
authors.lastname: Lerondel
authors.forename: Sergei
authors.initials: S
authors.lastname: Kostcheev
authors.forename: Pascal
authors.initials: P
authors.lastname: Royer