On a Boundary Element Method (BEM) for the Nonloeal Hydrodynamie Response of a Nanoantenna

Within the framework of the Boundary Element Method (BEM), we develop a computational scheme to account for nonlocal hydrodynamic effects in three -dimensional metallic nanoparticles of arbitrary shape. In contrast to conventional field-based methods, the reported scheme is formulated based on vector and scalar potentials. Especially, an extra scalar potential is introduced to describe longitudinal fields due to the hydrodynamic motion of electrons. The computational scheme is demonstrated for a canonical structure, i.e. sphere, for far field properties, e.g. scattering cross sections, and an excellent agreement is found with generalized Mie theory.