Linearized Fluid Model for Plasmon Oscillations in Metallic Nanoparticles

The paper deals with the numerical study of the electromagnetic response of a metallic nanoparticle to an external electromagnetic field, within the framework of the classical electrodynamics. The conduction electrons of the nanoparticle are modeled as a compressible electron fluid, whose dynamics are described by means of the linearized hydrodynamic equations. The electromagnetic field scattered by the nanoparticle is evaluated by a full-wave 3-D model based on an integral equation where the unknown is the current density. The fluid quantum pressure arising from the kinetic energy of the degenerate conduction electron gas gives rise to non-local effects that strongly influence the plasmon oscillations.