Plasmonic hybridization in the presence of topological insulators

Abstract

The hybridization model for the coupled plasmons of a metallic nanoshell is generalized to the case with the presence of topological insulator materials via the application of axion electrodynamics. A new approach has to be adopted in the Lagrangian formulation of the coupling dynamics between the surface and cavity plasmons to account for the axion-induced charges on the boundary surfaces. It is found that, as observed previously from numerical studies in the literature, the hybridization model predicts that a topological magneto-electric effect will lead to red shifts on both the coupled bonding and anti-bonding modes–more significant for the higher-order bonding modes with the increase of the axion coupling parameter.