Analogue of Electromagnetically Induced Transparency in a Terahertz Metamaterial

TL;DR

This paper demonstrates a terahertz metamaterial that mimics electromagnetically induced transparency through interference of resonances, enabling potential slow light applications and exploration of quantum phenomena in metallic structures.

Contribution

It introduces a novel planar metamaterial design that achieves EIT-like transparency at terahertz frequencies via independent excitation of resonances with different lifetimes.

Findings

Spectral transparency window observed at terahertz frequencies.

Large group index and low losses confirmed by simulations.

Potential for slow light and quantum phenomena exploration.

Abstract

We experimentally demonstrate at terahertz frequencies that a planar metamaterial exhibits a spectral response resembling electromagnetically induced transparency. The metamaterial unit cell consists of a split ring surrounded by another closed ring where their dimensions are such that their excitable lowest order modes have identical resonance frequencies but very different life times. Terahertz time-domain spectroscopy verifies that the interference of these two resonances results in a narrow transparency window located within a broad opaque region. In contrast to previous studies this enhanced transmission is achieved by independently exciting two resonances in which their coupling to the radiation field, and thus their linewidth, differs strongly. Rigorous numerical simulations prove that the transparency window is associated with a large group index and low losses, making the design potentially useful for slow light applications. This experiment opens an avenue to explore quantum mechanical phenomena using localized resonances in metallic structures,