ABSTRACT
Within the last two decades the investigation of metal nanoparticles
(MNPs) has attracted enormous interest in physics, physical
chemistry and even molecular biology (for a recent review see
[1, 2]). Considering MNPs with an extension ranging from some
nm up to some 100 nm, a multitude of experimental arrangements
and effects have been studied. The central observation here is the
strong response of the MNP electrons to external electromagnetic
perturbations. This response takes place via the formation of
surface plasmons representing collective motions of the metal
conduction band electrons. Since the number of involved electrons
is huge, the MNP absorption and scattering cross sections are
large. The incoming field is drastically altered, subwavelength
localization of electromagnetic energy appears, and high-intensity
hot spots of field strength are formed near the surface of the
MNP. When placing molecules, molecular complexes, biomolecules,
semiconductor quantum dots, or nanocrystals in the proximity of an
MNP, their optical and transport properties are essentially modified
[1]. The simplest effect would be the increased optical excitation of
a quantum system near an MNP due to the field enhancement of an
externally applied laser pulse.
