Towards negative index self-assembled metamaterials

TL;DR

This paper explores the use of hollow metallic nanoparticles in self-assembled metamaterials to achieve negative index properties, addressing key challenges of resonance strength and absorption for practical applications.

Contribution

It introduces hollow metallic nanoparticles as a novel meta-atom design, enabling stronger magnetic responses and reduced absorption in self-assembled negative index metamaterials.

Findings

Hollow metallic nanoparticles enhance resonance strength.

Reduced absorption improves metamaterial performance.

Potential for practical negative index materials.

Abstract

We investigate the magnetic response of meta-atoms that can be fabricated by a bottom-up technique. Usually such meta-atoms consist of a dielectric core surrounded by a large number of solid metallic nanoparticles. In contrast to those meta-atoms considered thus far, we study here for the first time hollow metallic nanoparticles (shells). In doing so we solve one of the most pertinent problems of current self-assembled metamaterials, namely implementing meta-atoms with sufficiently large resonance strength and small absorption. Both conditions have to be met for deep sub-wavelength meta-atoms to obtain effectively homogeneous metamaterials which may be meaningfully described by negative material parameters. Eventually we show that by using these findings self-assembled negative index materials come in reach.