Asymmetric Backscattering from the Hybrid Magneto-Electric Meta Particle

TL;DR

This paper demonstrates a hybrid magneto-electric particle that exhibits strong asymmetric backscattering, with potential applications in metamaterials, cloaking, and holography, supported by theoretical, numerical, and experimental results.

Contribution

It introduces a novel hybrid magneto-electric particle with asymmetric scattering properties, validated through theory, simulations, and experiments at GHz frequencies.

Findings

Backscattering asymmetry achieved with HMEP

Zero scattering cross section from one side at specific frequency

Experimental results confirm theoretical predictions

Abstract

The optical theorem relates the total scattering cross-section of a given structure with its forward scattering, but does not impose any restrictions on other directions. Strong backward-forward asymmetry in scattering could be achieved by exploring retarded coupling between particles, exhibiting both electric and magnetic resonances. Here, a hybrid magneto-electric particle (HMEP), consisting of a split ring resonator acting as a magnetic dipole and a wire antenna acting as an electric dipole, is shown to possess asymmetric scattering properties. When illuminated from opposite directions with the same polarization of the electric field, the structure has exactly the same forward scattering, while the backward scattering is drastically different. The scattering cross section is shown to be as low as zero at a narrow frequency range when illuminated from one side, while being maximal at the same frequency range when illuminated from the other side. Theoretical predictions of the phenomena are supported with both numerical and experimental conformations, obtained at the GHz frequency range, and all are in a good agreement with each other. HMEP meta-particles could be used as building blocks for various metamaterials assembling solar cells, invisibility cloaks, holographic masks and more.