Impact of Nonuniform Electron Density on Plasmonic Properties of Metal Nanoparticles

The interfacial nonuniformity of the electron density that occurs in metals as a result of atomic imperfections can strongly affect the plasmonic properties of metallic nanostructures. Under certain conditions, it induces the bulk plasmon resonance in the transition area and can significantly change scattering and absorption of light by metallic nanostructures in a broad frequency range. This effect is numerically demonstrated for radially nonuniform spherical silver nanoparticles and analytically investigated with respect to the resonant coupling with the dipolar surface plasmons of the metal core.