title: Multimodal plasmonics in fused colloidal networks.
abstract: Harnessing the optical properties of noble metals down to the nanometre scale is a key step towards fast and low-dissipative information processing. At the 10-nm length scale, metal crystallinity and patterning as well as probing of surface plasmon properties must be controlled with a challenging high level of precision. Here, we demonstrate that ultimate lateral confinement and delocalization of surface plasmon modes are simultaneously achieved in extended self-assembled networks comprising linear chains of partially fused gold nanoparticles. The spectral and spatial distributions of the surface plasmon modes associated with the colloidal superstructures are evidenced by performing monochromated electron energy-loss spectroscopy with a nanometre-sized electron probe. We prepare the metallic bead strings by electron-beam-induced interparticle fusion of nanoparticle networks. The fused superstructures retain the native morphology and crystallinity but develop very low-energy surface plasmon modes that are capable of supporting long-range and spectrally tunable propagation in nanoscale waveguides.
authors.affiliation: CEMES CNRS UPR 8011, 29 rue J. Marvig, 31055 Toulouse Cedex 4, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Teulle
authors.affiliation: Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, 117602 Singapore, Singapore.
authors.forename: Michel
authors.initials: M
authors.lastname: Bosman
authors.affiliation: CEMES CNRS UPR 8011, 29 rue J. Marvig, 31055 Toulouse Cedex 4, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Girard
authors.affiliation: CEMES CNRS UPR 8011, 29 rue J. Marvig, 31055 Toulouse Cedex 4, France.
authors.forename: Kargal L
authors.initials: KL
authors.lastname: Gurunatha
authors.affiliation: Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Cantocks Close, Bristol BS8 1TS, UK.
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.affiliation: Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Cantocks Close, Bristol BS8 1TS, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Mann
authors.affiliation: CEMES CNRS UPR 8011, 29 rue J. Marvig, 31055 Toulouse Cedex 4, France.
authors.forename: Erik
authors.initials: E
authors.lastname: Dujardin