Quantum corrected model for plasmonic nanoparticles: A boundary element method implementation

We present a variant of the recently developed quantum corrected model (QCM) for plasmonic nanoparticles [Nature Commun. 3, 825 (2012)] using non-local boundary conditions. The QCM accounts for electron tunneling in narrow gap regions of coupled metallic nanoparticles, leading to the appearance of new charge transfer plasmons. Our approach has the advantages that it emphasizes the non-local nature of tunneling and introduces only contact resistance, but not ohmic losses through tunneling. Additionally, it can be implemented much easier in boundary element method (BEM) approaches. We develop the methodology for the QCM using non-local boundary conditions, and present simulation results of our BEM implementation which are in good agreement with those of the original QCM.