Invited Paper PL-MoM8
Plasmon Hybridization: Understanding the Nature of Plasmons in Complex Nanostructures

Monday, October 15, 2007, 10:20 am, Room 619

The recent observation that certain metallic nanoparticles possess plasmon resonances that depend very sensitively on the shape of the nanostructure has led us to a fundamentally new understanding of the plasmon resonances supported by metals of various geometries. This picture- "plasmon hybridization",¹ reveals that the collective electronic resonances in metallic nanostructures are mesoscopic analogs of the wave functions of simple atoms and molecules, interacting in a manner that is analogous to hybridization in molecular orbital theory. The plasmon hybridization picture can be applied to an entire family of plasmonic nanostructures of various geometries, such as "nanoshells", "nanoeggs", "nanorice", nanoparticle aggregates, and finite nanoparticles interacting with extended substrates such as metallic films and wires.² The approach can also be used to provide a microscopic understanding of the plasmon in highly irregular nanostructures such as "nanostars",³ electromigrated gaps in bowtie junctions,⁴ and individual and concentric nanorings. The new theoretical insight gained through this approach provides an important conceptual foundation for the development of new plasmonic structures that can serve as surface plasmon resonance (SPR) sensors and as substrates for surface enhanced spectroscopies such as surface enhanced Raman scattering (SERS) or surface enhanced infrared absorption spectroscopy (SEIRA), subwavelength plasmonic waveguides, and nanoantennas for on-chip communication.

¹E. Prodan et Al., Science 302(2003)419
²H. Wang et Al., Accounts of Chemical Research 40(2007)53
³F. Hao et Al., Nano Lett. 7(2007)729
⁴D.R. Ward et Al., Nano Lett. 7(2007)1396