Interface-induced dephasing of Mie plasmon polaritons

Abstract

Surface and, in particular, interface effects influence all physical and chemical properties of nanostructured matter. Mie surface plasmon polaritons (MPPs) in metallic nanoparticles are excellent and sensitive sensors for optical investigation of these effects of realistic particles since their lifetimes due to dephasing (decoherence) effects and their resonance energies drastically depend upon the chemistry and topology of their surfaces/interfaces. A survey is given over some results of our own long term research on MPPs which started, in fact, as early as 1969. Theoretical models and experiments concerning the A parameter, the δ n parameter, MPP phase decoherence and static and dynamic interface charge transfer effects (“chemical interface damping”) are briefly summarized. The effect of radiation damping is disregarded throughout: we assume the particle sizes to be small enough to justify this simplification, which makes it easier to draw conclusions from the MPPs on nanomaterial properties. Obviously, there is a wide field for future research concerning particle interfaces on the basis of Mie’s theory. On the other hand, all of these effects have to be incorporated into Mie’s theory to obtain a “modern” version which is reliable on a quantitative level to describe experimental data.