Large group delay in a microwave metamaterial analogue of electromagnetically induced transparency

TL;DR

This paper demonstrates a planar microwave metamaterial that exhibits electromagnetically induced transparency-like behavior with high group delay and low absorption, achieved through structural symmetry without symmetry breaking.

Contribution

It introduces a symmetric metamaterial design that achieves EIT-like resonance with high quality factor and large group index, avoiding the need for symmetry breaking.

Findings

Achieved low absorption (<10%) in the metamaterial.

Demonstrated large group index (~30).

Realized EIT-like resonance without symmetry breaking.

Abstract

We report on our experimental work concerning a planar metamaterial exhibiting classical electromagnetically induced transparency (EIT). Using a structure with two mirrored split-ring resonators as the dark element and a cut wire as the radiative element, we demonstrate that an EIT-like resonance can be achieved without breaking the symmetry of the structure. The mirror symmetry of the metamaterial's structural element results in a selection rule inhibiting magnetic dipole radiation for the dark element, and the increased quality factor leads to low absorption (<10%) and large group index (of the order of 30).