Symmetry breaking in individual plasmonic nanoparticles.
The plasmon resonances of a concentric metallic nanoshell arise from the hybridization of primitive plasmon modes of the same angular momentum on its inner and outer surfaces. For a nanoshell with an offset core, the reduction in symmetry relaxes these selection rules, allowing for an admixture of dipolar components in all plasmon modes of the particle. This metallodielectric nanostructure with reduced symmetry exhibits a core offset-dependent multipeaked spectrum, seen in single-particle spectroscopic measurements, and exhibits significantly larger local-field enhancements on its external surface than the equivalent concentric spherical nanostructure.
Wang
Hui
H
Department of Chemistry, Laboratory for Nanophotonics, Rice University, Houston, TX 77005, USA.
Wu
Yanpeng
Y
Lassiter
Britt
B
Nehl
Colleen L
CL
Hafner
Jason H
JH
Nordlander
Peter
P
Halas
Naomi J
NJ
D055590:Electromagnetic Phenomena; D049329:Nanostructures; D013057:Spectrum Analysis