Plasmon excitation theory

In the framework of many-body perturbation theory, we have studied the nonlinear interaction of charged particles with a free gas of interacting electrons. We have presented general procedures to calculate the nonlinear potential induced by charged particles moving in an inhomogeneous electron system, the Zj contribution to the stopping power of a FEG, and double-plasmon excitation probabilities. 

The composition and chemical state of surface layers of glasses determine their emission capacity, i.e., the secondary electron emission coefficient. The mechanism of secondary electron emission is studied in [51]. The authors developed theory of a plasmon mechanism of secondary emission of electrons by dielectrics, in which the main role is attributed to the process of generation and disintegration of plasmons arising as a consequence of inelastic interaction of primary electrons with the electron structirre of solids. The probability of plasmon excitation depends on the concentration of valence electrons and the minimum... 

It should be pointed out that both, the reflectivity curve R(0), as well as, the angular distribution of the optical field intensity Is(9) are described by Fresnel s equations, i.e., can be calculated based on Maxwell s theory of such a layered architecture. Once R(6) is calculated by using the dielectric functions and the thicknesses of the involved materials (prism, metal layer, functional interfacial binding matrix, dielectric superstrate) the optical intensity and its angular dependence ls(0) can be calculated without any additional free parameter. It is important to keep in mind that for fluorescence spectroscopy with surface plasmon excitation it is the optical intensity Ij (and its angular dependence) that controls the excitation process of the fluorophores. 

In light of the computational cost associated with many-body theories, it is not feasible to apply a quantum mechanics treatment to a full-scale PDSSC, which by definition requires a large number of conduction electrons to induce surface plasmon excitation. On the other hand, the continuum models have become the de facto means for describing the macroscopic optical response in these systems. Therefore, it is natural to divide a PDSSC conceptually into two parts, one for the photoactive component and the other for the plasmonic constituent. Here the photoactive component is usually composed of organic dye and/or inorganic metal complex molecules, the plasmon constituent is typically made of metallic or semiconductor nanoparticles and the coupling between them is commonly referred to as the molecule- particle interaction. Several optical... 

To summarize, for photon energies above the plasmon energies (and away from other excitation energies), the electromagnetic fields can be described adequately with macroscopic dielectric theory. 

Surface plasmons (SPs) are collective electronic excitations near the surfaces of metallic structures. They can usually be described well with classical electromagnetic theory and correspond to electromagnetic fields that are localized and relatively intense near the metallic surfaces [1, 2]. These properties make them potentially useful for a variety of applications in optoelectronics, chemical and biological sensing, and other areas. Metallic nanostructures such as metal nanoparticles and nanostructured thin metal films, particularly those composed of noble metals such as silver or gold, are of special interest because often their SPs can be excited with visible-UV light and are relatively robust. 

New calculations of the various contributions to the second-order stopping power of a uniform FEG coming from the excitation of e-h pairs and plasmons have been reported. We have found that the equipartition rule, vahd within first-order perturbation (linear-response) theory, cannot be extended to higher orders in the external perturbation. We have also found that contributions from collective excitations to the Zj term are small. 

Arya and Zeyher " develop a general many-body theory for SERS. In the limit of a planar surface and only plasmon contributions to the interactions, they find an enhancement of a factor of 100 for the renormalization model and it is relatively weakly dependent on the excitation frequency. This is for silver of course. For Cu or Au, they predict even smaller image effects, <10. 

In this chapter we present an electromagnetic theory of surface plasmons based on theoretical analysis of light propagation in planar metal/dielectric waveguides. The main characteristics of surface plasmons propagating along metal-dielectric and dielectric-metal-dielectric waveguides are introduced and methods for optical excitation of surface plasmons are discussed. 

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