Non-local effects in the plasmons of strongly interacting nanoparticles, dimers, and waveguides

TL;DR

This paper investigates non-local effects in noble metal nanostructures, revealing significant blueshifts and field quenching in plasmons, which are crucial for designing advanced optical and photovoltaic devices.

Contribution

It introduces a non-local extension of dielectric functions to accurately predict plasmon resonance shifts and field reductions in nanoscale metallic structures.

Findings

Resonance shifts up to 10% due to non-local effects

Order of magnitude reduction in near-field intensity at sub-2 Å scales

Provides a design roadmap for plasmonic nanostructures

Abstract

Non-local effects in the optical response of noble metals are shown to produce significant blueshift and near-field quenching of plasmons in nanoparticle dimers, nanoshells, and thin metal waveguides. Compared with a local description relying on the use of frequency-dependent dielectric functions, we predict resonance shifts as large as 10% and field-intensity reduction of an order of magnitude at inter-particle distances or metal thicknesses below 2 \AA. Our results are based upon the specular-reflection model combined with a suitable non-local extension of measured local dielectric functions. We present a roadmap to design plasmon resonances in nanometer metallic elements with application to optical antennas and improved photovoltaic, light-emitting, and sensing devices.