Engineering Electromagnetic Properties of Periodic Nanostructures Using Electrostatic Resonances

TL;DR

This paper demonstrates how the electromagnetic properties of periodic nanostructures can be engineered through electrostatic resonances, revealing multiple wave bands, duality relations, and sub-wavelength imaging capabilities.

Contribution

It introduces a method to engineer nanostructure electromagnetic properties using electrostatic resonances, including the discovery of multiple wave bands and sub-wavelength imaging.

Findings

Multiple wave propagation bands with wavelengths longer than the nanostructure period.

Identification of bands described by quasi-static effective dielectric permittivity.

Development of a negative magnetic permeability band enabling sub-wavelength imaging.

Abstract

Electromagnetic properties of periodic two-dimensional sub-wavelength structures consisting of closely-packed inclusions of materials with negative dielectric permittivity $\epsilon$ in a dielectric host with positive $\epsilon_h$ can be engineered using the concept of multiple electrostatic resonances. Fully electromagnetic solutions of Maxwell's equations reveal multiple wave propagation bands, with the wavelengths much longer than the nanostructure period. It is shown that some of these bands are described using the quasi-static theory of the effective dielectric permittivity $\epsilon_{qs}$, and are independent of the nanostructure period. Those bands exhibit multiple cutoffs and resonances which are found to be related to each other through a duality condition. An additional propagation band characterized by a negative magnetic permeability develops when a magnetic moment is induced in a given nano-particle by its neighbors. Imaging with sub-wavelength resolution in that band is demonstrated.