title: Optical spectroscopy of conductive junctions in plasmonic cavities.
abstract: The optical properties of a nanoparticle dimer bridged by a conductive junction depend strongly on the junction conductivity. As the conductivity increases, the bonding dimer plasmon blueshifts and broadens. For large conductance, a low energy charge transfer plasmon also appears in the spectra with a line width that decreases with increasing conductance. A simple physical model for the understanding of the spectral feature is presented. Our finding of a strong influence of junction conductivity on the optical spectrum suggests that plasmonic cavities might serve as probes of molecular conductance at elevated frequencies not accessible through electrical measurements.
authors.affiliation: Donostia International Physics Center and Centro de Física de Materiales, Centro Mixto CSIC-UPV/EHU, Paseo Manuel Lardizabal 4, 20018 Donostia-San Sebastián, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Pérez-González
authors.forename: N
authors.initials: N
authors.lastname: Zabala
authors.forename: A G
authors.initials: AG
authors.lastname: Borisov
authors.forename: N J
authors.initials: NJ
authors.lastname: Halas
authors.forename: P
authors.initials: P
authors.lastname: Nordlander
authors.forename: J
authors.initials: J
authors.lastname: Aizpurua