Achievement

Symmetry breaking in plasmonic systems can lead to many interesting effects. We have studied symmetry breaking in one of the simplest nanostructures, a nanoparticle dimer consisting of two gold nanoparticles or a nanoparticle and a nanoshell adjacent to each other. Remarkable phenomenon observed include Fano resonances, avoided crossing behavior, and a surprising dependence of the scattering spectrum on the direction of excitation. In a series of studies, using polarization-dependent dark-field microspectroscopy, we experimentally probe and theoretically analyze these properties in heterodimer nanostructures, where nanoparticle size and plasmon resonance frequency are varied systematically. These studies expand our understanding of the range of physical effects that can be observed in adjacent metallic nanostructures.

Lisa V. Brown*, J. Britt Lassiter* et al. "Heterodimers: Plasmonic Properties of Mismatched Nanoparticle Pairs" ACS Nano 4, 819-832, (2010)