Absorption of low-frequency radiation by small metal particles: a semiclassical random-phase-approximation

Abstract

We introduce a theory for the absorption of electromagnetic radiation by small metal particles, which generalises the random phase approximation by incorporating both electric and magnetic dipole absorption within a unified self-consistent scheme. We demonstrate the equivalence of the new approach to a superficially dissimilar perturbative approach. We show how to obtain solutions to the self-consistent equations using a classical approximation, taking into account the non-locality of the polarisability and the conductivity tensor. We discuss the nature of the self-consistent solutions for diffusive and ballistic electron dynamics.

Imperfect Perfect Lens

“…To take into account the effect of boundaries, we assume specular reflection of electrons from the surface. As was shown in ref , the ideal specular reflection implies that a nonlocal electrostatic problem for a half-infinite metal is equivalent to a problem in bulk metal where E ⊥ ( x , y , 0) is the normal electric field at this surface, φ i is the field potential in the metal, and ε is the nonlocal dielectric response operator. The Dirac delta function emulates the boundary condition at the metal surface.…”