Hyper-Plasmonics: hyperbolic modes of a metal-dielectric interface

TL;DR

This paper introduces hyperbolic layers at metal-dielectric interfaces caused by non-local electron response, leading to new surface waves called hyper-plasmons that outperform traditional plasmons in confinement and bandwidth.

Contribution

It reveals the formation of hyperbolic layers due to non-locality, supporting hyper-plasmons with enhanced propagation and confinement, extending plasmonic device capabilities.

Findings

Hyperbolic layer formation near metal-dielectric interfaces.

Support for hyper-plasmons with longer propagation and stronger confinement.

Extended operational bandwidth of plasmonic devices.

Abstract

Plasmon resonance, with strong coupling of light to electrons at a metal-dielectric interface, allows light confinement and control at subwavelength scale. It's fundamentally limited by the inherent mobility of the electrons, leading to the corresponding non-locality of the electromagnetic response. We report that this non-locality also results in the formation of a hyperbolic layer near the metal-dielectric interface, with a strong anisotropy of its electromagnetic response. While the resulting "hyperbolic blockade" leads to the suppression of the conventional plasmon resonance, the hyperbolic layer also supports an entirely new class of surface waves, that offer longer propagation distance and stronger field confinement, simultaneously. Furthermore, these "hyper-plasmons" are not limited to the proximity of the plasmon resonance, which dramatically extends the operational bandwidth of plasmonic devices.