Hydrodynamic model for plasmonics: a macroscopic approach to a microscopic problem.

In this concept, we present the basic assumptions and techniques underlying the hydrodynamic model of electron response in metals and demonstrate that the model can be easily incorporated into computational models. We discuss the role of the additional boundary conditions that arise due to nonlocal terms in the modified equation of motion and the ultimate impact on nanoplasmonic systems. The hydrodynamic model captures much of the microscopic dynamics relating to the fundamental quantum mechanical nature of the electrons and reveals intrinsic limitations to the confinement and enhancement of light around nanoscale features. The presence of such limits is investigated numerically for different configurations of plasmonic nanostructures.