Generalized electromagnetic theorems for non-local plasmonics

TL;DR

This paper extends fundamental electromagnetic theorems within the semiclassical hydrodynamic model to better understand non-local plasmonic effects, highlighting the importance of quantum considerations in ultraconfined light-matter interactions.

Contribution

It generalizes absorption volume density and reciprocity theorems for non-local plasmonics using the hydrodynamic model, improving accuracy over classical approaches.

Findings

Generalized theorems validated numerically.

Classical expressions lead to significant discrepancies.

Highlights the importance of non-local effects in plasmonics.

Abstract

The ultraconfined light of plasmonic modes put their effective wavelength close to the mean free path of electrons inside the metal electron gas. The Drude model, which can not take the repulsive interactions of electrons into account, then clearly begins to show its limits. In an intermediate length scale where a full quantum treatment is computationally prohibitive, the semiclassical hydrodynamic model, instrinsically non-local, has proven successful. Here we generalize the expression for the absorption volume density and the reciprocity theorem in the framework of this hydrodynamic model. We validate numerically these generalized theorems and show that using classical expressions instead leads to large discrepancies.