Molecular spectroscopic view of surface plasmon enhanced resonance Raman scattering

PHYS 82

Anne Myers Kelley, amkelley@ucmerced.edu, School of Natural Sciences, University of California, Merced, PO Box 2039, Merced, CA 95344
The enhancement of resonance Raman scattering by the plasmon resonance of a metal nanoparticle is developed by treating the molecule-metal interaction as transition dipole coupling between the molecular electronic transition and the much stronger optical transition of the nanoparticle. A density matrix treatment is used to account for coupling of the molecular and nanoparticle transitions to the electromagnetic field, energy transfer between the molecule-excited and nanoparticle-excited states, and dephasing processes that generate the linewidths of both transitions. This fully quantum mechanical approach reproduces the interference effects observed in extinction spectra of J-aggregated dyes adsorbed to metal nanoparticles, and makes testable predictions for surface enhanced resonance Raman profiles in systems of well defined geometry.