title: Coupled multipolar interactions in small-particle metallic clusters.
abstract: We propose a new formalism for computing the optical properties of small clusters of particles. It is a generalization of the coupled dipole-dipole particle-interaction model and allows one in principle to take into account all multipolar interactions in the long-wavelength limit. The method is illustrated by computations of the optical properties of N = 6 particle clusters for different multipolar approximations. We examine the effect of separation between particles and compare the optical spectra with the discrete-dipole approximation and the generalized Mie theory.
authors.affiliation: Department of Materials Science, University of Uppsala, The Angstrom Laboratory, Sweden,. Pustovit.Vitaly@angstrom.uu.se
authors.forename: Vitaly N
authors.initials: VN
authors.lastname: Pustovit
authors.forename: Juan A
authors.initials: JA
authors.lastname: Sotelo
authors.forename: Gunnar A
authors.initials: GA
authors.lastname: Niklasson