Metal photoluminescence (MPL) originates from radiative recombination of photoexcited core holes and conduction band electrons. In metal nanostructures, MPL is enhanced due to the surface plasmon local field effect. We identify another essential process in plasmon-assisted MPL-excitation of Auger plasmons by core holes-that hinders MPL from small… (More)
We study the effect of Coulomb correlations on the ultrafast optical dynamics of small metal particles. We demonstrate that a surface-induced dynamical screening of the electron-electron interactions leads to quasiparticle scattering with collective surface excitations. In noble-metal nanoparticles, it results in an interband resonant scattering of d-holes… (More)
We study finite-size effects in surface-enhanced Raman scattering (SERS) from molecules adsorbed on small metal particles. Within an electromagnetic description of SERS, the enhancement of the Raman signal originates from the local field of the surface plasmon resonance in a nanoparticle. With decreasing particle sizes, this enhancement is reduced due to… (More)
We develop a theory describing the effects of many–particle Coulomb correlations on the coherent ultrafast nonlinear optical response of semiconductors and metals. Our approach is based on a mapping of the nonlinear optical response of the " bare " system onto the linear response of a " dressed " system. The latter is characterized by effective… (More)
We study the energy spectrum of a system of localized states coupled to a 2D electron gas in strong magnetic field. If the energy levels of localized states are close to the electron energy in the plane, the system exhibits a kind of collective behavior analogous to the Dicke effect in optics. The latter manifests itself in " trapping " of electronic states… (More)
A plasmon-mediated mechanism of cooperative emission by an ensemble of dipoles near a metal nanoparticle is studied. The radiation is dominated by plasmonic super-radiant states which survive dipole-dipole interactions and non-radiative losses in the metal.
A new theoretical approach for the calculation of optical properties of complex solutions is proposed. It is based on a dielectric matrix εm with included small metallic inclusions (less than 3 nm) of spherical shape. We take into account the mutual interactions between the inclusions and the quantum finite-size effects. On the basis of the effective medium… (More)