Anderson localization versus hopping asymmetry in a disordered lattice

TL;DR

This paper explores how disorder and non-Hermiticity influence wave behavior in a 1D Hatano-Nelson lattice, revealing distinct phases of wave propagation and counter-intuitive effects on wave velocity.

Contribution

It demonstrates the complex interplay between Anderson localization and non-Hermitian skin effects in a disordered lattice, highlighting novel wave diffraction phases.

Findings

Disorder and non-Hermiticity produce distinct wave propagation phases.

Counter-intuitive relationship between disorder strength and wave velocity.

Existence of skin modes influencing wave dynamics.

Abstract

In the framework of non-Hermitian photonics, we investigate the interplay between disorder and non-Hermiticity in a one-dimensional Hatano-Nelson lattice. While Anderson localization dictates the wave's evolution in conservative random systems, the introduction of non-Hermiticity tends to force the beam to unidirectionally propagate towards one edge of the potential due to the existence of skin modes. As we show, the antagonism between these effects results in qualitatively distinct phases of wave diffraction, including counter-intuitive characteristics regarding the relationship between the strength of disorder and the wavepacket's velocity.