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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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Prof. Stephan Link, Rice University
Collective plasmon modes in nanoparticle assemblies
Physical Chemistry Seminar Series
In order to incorporate plasmonic nanoparticles into functional devices it is necessary to understand how surface plasmons couple as particles are arranged into ordered structures. Bottom-up assembly of chemically prepared nanoparticles facilities strong plasmon coupling due to short interparticle distances, but also gives to rise to defects in particle size, shape, and ordering. Single particle spectroscopy of plasmonic nanoparticle assemblies, especially when correlated with structural characterization using scanning electron microscopy, allows one to gain a detailed understanding about collective plasmon modes. We have used polarization sensitive dark-field scattering spectroscopy covering a broad spectral range from the visible up to 2000 nm and polarization dependent photothermal imaging to separately investigate radiative and nonradiative coupling in one-dimensional assemblies of plasmonic nanoparticles. For both scattering and absorption, we observed collective plasmon modes that are highly polarized along the main axis of the one-dimensional nanoparticle chain and red-shifted from the plasmon resonance of the individual constituents. These collective plasmon modes are compared to plasmon antenna modes of continuous nanorods with varying length and width. Furthermore, we have developed a fluorescence based method to visualize plasmon propagation in one-dimensional nanostructures.
For more information contact Prof. Christine Payne (404-385-3125) or Prof. Mostafa El-Sayed (404-894-0292).
