Broadband and Wide-Angle Nonreciprocity with a Nonhermitian Metamaterial

TL;DR

This paper presents a theoretical design of a broadband, wide-angle nonreciprocal metamaterial using PT-symmetric loss and gain layers, enabling nonreciprocal light transmission in the visible spectrum.

Contribution

It introduces a novel non-Hermitian metamaterial with broadband and wide-angle nonreciprocity based on PT symmetry and nonlinear effects.

Findings

Achieves nonreciprocal transmission over 50 nm wavelength range

Demonstrates wide-angle nonreciprocity up to 60 degrees

Shows strong modification of bandstructure with loss and gain

Abstract

We theoretically demonstrate a non-hermitian metamaterial exhibiting broadband and wide-angle nonreciprocity. The metamaterial consists of planar metal-dielectric layers with a Parity-Time (PT) symmetric distrubtion of loss and gain. With increasing loss and gain, the bandstructure and bandgap are strongly modified; further, the PT potential leads to distinct internal field distributions when illuminated from different sides. Including nonlinearities arising from natural loss and gain saturation leads to nonreciprocal transmission in the visible over a 50 nm wavelength and 60$^{\circ}$ degree angular range.