Superdirective Leaky Radiation from a PT-Synthetic Metachannel

TL;DR

This paper introduces a PT-synthetic metachannel that achieves superdirective leaky radiation with adjustable beam angles, enabling advanced antenna designs and applications requiring extreme dielectric properties.

Contribution

It presents a novel PT-synthetic metasurface design that supports low-loss, nearly undamped fast-wave propagation and high directivity radiation, expanding practical applications of PT-symmetric systems.

Findings

High directivity leaky radiation achieved

Beam angle tunable via gain-loss parameter

Supports applications in ENZ and low-index regimes

Abstract

Spectral singularities appearing in parity-time (PT)-symmetric non-Hermitian optical systems have aroused a growing interest due to their new, exhilarating applications, such as bifurcation effects at exceptional points and the coexistence of coherent perfect absorber and laser (so-called CPAL point). We introduce here how the concept of CPAL action provoked in PT-symmetric metasurfaces can be translated into practical implementation of a low-loss zero- or low-index channel supporting a nearly undamped fast-wave propagation. Such a PT-synthetic metachannel shows the capability to produce a high-directivity leaky radiation, with a beam angle that can be altered by varying the gain-loss parameter. The proposed structure may enable new kinds of super-directivity antennas working in different regions of the electromagnetic spectrum, as well as various applications that demand extreme dielectric properties, such as epsilon-near-zero (ENZ).