Composite metamaterials with dual-band magnetic resonances in the terahertz frequency regime

TL;DR

This paper reports the design and fabrication of composite terahertz metamaterials exhibiting dual-band magnetic resonances, confirmed through experiments and simulations, advancing the understanding of magnetic responses in the terahertz regime.

Contribution

It introduces a novel composite metamaterial structure with dual-band magnetic resonances and provides experimental and simulation validation of these resonances.

Findings

Dual-band magnetic resonances at 4.40 THz and 8.64 THz observed

Experimental results agree with numerical simulations

Resonances originate from specific current distributions in the structure

Abstract

Composite metamaterials(CMMs) combining a subwavelength metallic hole array (i.e. one-layer fishnet structure) and an array of split-ring resonators(SRRs) on the same board are fabricated with gold films on silicon wafer. Transmission measurements of the CMMs in the terahertz range have been performed. Dual-band magnetic resonances, namely, a LC resonance at 4.40 THz and an additional magnetic resonance at 8.64 THz originating from the antiparallel current in wire pairs in the CMMs are observed when the electrical field polarization of the incident light is parallel to the gap of the component SRR. The numerical simulations agree well with the experimental results and further clarify the nature of the dual-band magnetic resonances.