Analytical study of the plasmonic modes of metal nanoparticle circular array

TL;DR

This paper provides an analytical study of plasmonic modes in metal nanoparticle circular arrays, revealing how certain modes exhibit suppressed radiative loss due to dipolar cancellation, with linewidth decreasing exponentially as array size grows.

Contribution

It offers closed-form solutions for eigenmodes and identifies the mode with the highest quality factor as an antiphase mode, explaining loss suppression mechanisms.

Findings

Antiphase mode has the highest quality among plasmonic modes.

Radiative linewidth decreases exponentially with increasing particle number.

Dipolar radiation cancellation explains loss suppression.

Abstract

We analyze the plasmonic modes of a metal nanoparticle circular array. Closed form solutions to the eigenmode problem are given. For each polarization, the plasmonic mode with the highest quality is found to be an antiphase mode. We found that the significant suppression in radiative loss can be understood as the cancellation of the dipolar radiation term in the radiative linewidth. The remaining finite radiative linewidth decreases exponentially as the number of particle increases.