Dynamical Theory of Artificial Optical Magnetism Produced by Rings of Plasmonic Nanoparticles

TL;DR

This paper develops an analytical theory for plasmonic nanorings that achieve negative magnetic permeability and index at optical frequencies, offering improved performance over existing solutions by providing a more pure magnetic response.

Contribution

The paper introduces a detailed analytical model for plasmonic nanorings that demonstrates their ability to produce negative magnetic permeability and index at infrared and optical frequencies, with enhanced performance and reduced losses.

Findings

Nanoring configuration provides negative magnetic permeability at optical frequencies.

Analytical comparison shows superior performance over other negative index solutions.

Sensitivity analysis reveals bandwidth and loss characteristics of the magnetic response.

Abstract

We present a detailed analytical theory for the plasmonic nanoring configuration first proposed in [A. Alu, A. Salandrino, N. Engheta, Opt. Expr. 14, 1557 (2006)], which is shown to provide negative magnetic permeability and negative index of refraction at infrared and optical frequencies. We show analytically how the nanoring configuration may provide superior performance when compared to some other solutions for optical negative index materials, offering a more 'pure' magnetic response at these high frequencies, which is necessary for lowering the effects of radiation losses and absorption. Sensitivity to losses and the bandwidth of operation of this magnetic inclusion are also investigated in details and compared with other available setups.