Symmetry breaking in a plasmonic metamaterial at optical wavelength.
We numerically study the effect of structural asymmetry in a plasmonic metamaterial made from gold nanowires. It is reported that optically inactive (i.e., optically dark) particle plasmon modes of the symmetric wire lattice are immediately coupled to the radiation field, when a broken structural symmetry is introduced. Such higher order plasmon resonances are characterized by their subradiant nature. They generally reveal long lifetimes and distinct absorption losses. It is shown that the near-field interaction strongly determines these modes.
Christ
André
A
Nanophotonics and Metrology Laboratory, Ecole Polytechnique Fédéral de Lausanne, Lausanne, Switzerland. andre.christ@epfl
Martin
Olivier J F
OJ
Ekinci
Yasin
Y
Gippius
Nikolai A
NA
Tikhodeev
Sergei G
SG
D004583:Electrons; D006046:Gold / Q000737:chemistry*; D008280:Magnetics; D053770:Nanowires / Q000737:chemistry; D055095:Optics and Photonics; D013053:Spectrophotometry
D006046:Gold