title: Trimeric plasmonic molecules: the role of symmetry.
abstract: Artificial plasmonic molecules possess excitation modes that are defined by their symmetry and obey group theory rules, just like conventional molecules. We follow the evolution of surface-plasmon spectra of plasmonic trimers, assembled from equal-sized silver nanoparticles, as gradual geometric changes break their symmetry. The spectral modes of an equilateral triangle, the most symmetric structure of a trimer, are degenerate. This degeneracy is lifted as the symmetry is lowered when one of the vertex angles in opened, which also leads to a subtle transition between bright and dark modes. Our experimental results are quantitatively explained using numerical simulations and plasmon hybridization theory.
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel. lev.chuntonov@weizmann.ac.il
authors.forename: Lev
authors.initials: L
authors.lastname: Chuntonov
authors.forename: Gilad
authors.initials: G
authors.lastname: Haran
mesh_terms: D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D012834:Silver