Planar Metamaterial with Toroidal Moment

TL;DR

This paper demonstrates a planar metamaterial that exhibits a toroidal electromagnetic response using asymmetric split ring resonators, opening new avenues for subwavelength confinement and applications in optics and quantum technologies.

Contribution

It introduces a novel planar metamaterial design with toroidal response through asymmetric split ring resonators and structural symmetry manipulation.

Findings

Toroidal resonance observed in planar metamaterials.

Field maps show unique electromagnetic confinement.

High-Q responses due to Fano resonance and toroidal geometry.

Abstract

We observe toroidal response from a planar metamaterial comprised of asymmetric split ring resonators (ASRRs). It is showed that a toroidal-molecule can be constructed through rational arrangement of planar ASRRs as meta-atoms via manipulating structural symmetry of the meta-atoms. Field maps clearly indicate that the toroidal resonance paves new electromagnetic confinement style in a subwavelength scale. Planar scheme of manipulating the coupling among the ASRRs may stimulate research in optical region involving toroidal multipoles. Toroidal geometry together with the Fano resonance made high-Q response will have enormous potential applications in low-threshold lasing, cavity quantum electrodynamics and nonlinear processing.