Plasmonic nanoparticle monomers and dimers: From nano-antennas to chiral metamaterials

TL;DR

This paper reviews the physics of light interaction with plasmonic nanoparticles, deriving theoretical models for monomers and dimers, and explores their applications in nanoantennas and chiral metamaterials with potential for cost-effective optical devices.

Contribution

It provides a systematic theoretical investigation of light scattering on plasmonic monomers and dimers, and applies these models to design chiral metamaterials with elliptical dichroism.

Findings

Derived expressions for particle susceptibility and polarizability.

Calculated effective parameters for arrays of dimers as metamaterials.

Identified planar rod dimers as candidates for chiral optical metamaterials.

Abstract

We review the basic physics behind light interaction with plasmonic nanoparticles. The theoretical foundations of light scattering on one metallic particle (a plasmonic monomer) and two interacting particles (a plasmonic dimer) are systematically investigated. Expressions for effective particle susceptibility (polarizability) are derived, and applications of these results to plasmonic nanoantennas are outlined. In the long-wavelength limit, the effective macroscopic parameters of an array of plasmonic dimers are calculated. These parameters are attributable to an effective medium corresponding to a dilute arrangement of nanoparticles, i.e., a metamaterial where plasmonic monomers or dimers have the function of "meta-atoms". It is shown that planar dimers consisting of rod-like particles generally possess elliptical dichroism and function as atoms for planar chiral metamaterials. The fabricational simplicity of the proposed rod-dimer geometry can be used in the design of more cost-effective chiral metamaterials in the optical domain.