Excitation and Light Emission of Localized Plasmons for Metal Nanostructures in Dielectrics by Electron Beam

Abstract

Equations on excitation and light emission of the localized bulk and surface plasmons for metal nanostructures in dielectrics by electron beam are derived using the localized plasmon theory in the random phase approximation at high frequency condition. These are applied to calculate inelastic scattering probabilities of electron beams and light emission intensities by the localized plasmon excitations for metal nanospheres and ultrathin films in dielectrics using the quasi-static and electric dipole approximations. It is also assumed that local dielectric functions for metals and dielectrics have step function shapes at the metal and dielectric interfaces. It is found that the electron beams are inelastically scattered by the localized surface and bulk plasmons with various excitation modes, but the light is emitted only from the localized surface plasmons with specific excitation modes within these approximations.