Light scattering by adsorbates at Ag particles: Quantum-mechanical approach for energy transfer induced interfacial optical processes involving surface plasmons, multipoles, and electron-hole pairs

Abstract

A quantum‐mechanical approach for surface‐enhanced optical processes is given, which may solve an old controversy regarding the surface enhancement mechanisms: The present formalism contains three terms: The first is equivalent to the classically derived electromagnetic enhancement; the second represents a loss term due to a competitive dipole–multipole and dipole–electron‐hole pair coupling; and the third reveals an additional energy transfer induced gain for excitable molecules. Thus, the total pure surface enhancement can be much greater for ‘‘colored’’ species than for transparent ones.