Non-Hermitian control of localization in mosaic photonic lattices

TL;DR

This paper demonstrates how non-Hermitian engineering in mosaic photonic lattices with gain and loss regions can control wave localization and transport, revealing new ways to manipulate wave dynamics in disordered systems.

Contribution

It introduces a method to control wave spreading in disordered photonic lattices through uniform loss at alternating sites, advancing non-Hermitian wave transport techniques.

Findings

Loss at alternating sites suppresses wave spreading in disordered lattices.

Loss can also enhance wave transport depending on the disorder type.

The approach is demonstrated using discrete-time quantum walks in photonic lattices.

Abstract

Exploring the deep insights into localization, disorder, and wave transport in non-Hermitian systems is an emergent area of research of relevance in different areas of physics. Engineered photonic lattices, with spatial regions of optical gain and loss, provide a prime and simple physical platform for tailoring non-Hermitian Hamiltonians and for unveiling the intriguing interplay between disorder and non-Hermiticity. Here it is shown that in mosaic photonic lattices with on-site uncorrelated disorder or quasi-periodic order, the addition of uniform loss at alternating sites of the lattice results in the suppression or enhancement of wave spreading, thus providing a simple method for non-Hermitian control of wave transport in disordered systems. The results are illustrated by considering discrete-time quantum walks in synthetic photonic lattices.