Invisible non-Hermitian potentials in discrete-time photonic quantum walks

TL;DR

This paper demonstrates that under specific conditions, slowly-drifting Kramers-Kronig potentials act as invisible potentials in discrete-time photonic quantum walks, expanding the understanding of non-Hermitian phenomena in discretized optical systems.

Contribution

It reveals the existence of invisible potentials in discrete-time photonic quantum walks, a phenomenon previously known only in continuous optical media.

Findings

Kramers-Kronig potentials can be invisible in discrete-time systems

Invisible potentials depend on specific drift conditions

Expands the understanding of non-Hermitian effects in discretized photonics

Abstract

Discrete-time photonic quantum walks on a synthetic lattice, where both spatial and temporal evolution of light is discretized, have provided recently a fascinating platform for the observation of a wealth of non-Hermitian physical phenomena and for the control of light scattering in complex media. A rather open question is whether invisible potentials, analogous to the ones known for continuous optical media, do exist in such discretized systems. Here it is shown that, under certain conditions, slowly-drifting Kramers-Kronig potentials behave as invisible potentials in discrete-time photonic quantum walks.