Photon routing in disordered chiral waveguide QED ladders: Interplay between photonic localization and collective atomic effects

TL;DR

This paper investigates how disorder and collective atomic effects influence single-photon routing in chiral waveguide QED ladders, revealing robustness and high routing efficiency even with imperfections, relevant for quantum networks.

Contribution

It introduces a detailed analysis of photon routing in disordered chiral waveguide QED ladders, highlighting the interplay between atomic interactions and positional disorder.

Findings

Routing probability exceeds 90% in both periodic and disordered setups with 20 QEs.

Collective atomic effects remain robust against spontaneous emission and weak disorder.

Localization length and routing efficiency are maintained in chains of up to 20 QEs.

Abstract

In recent years, photon routing has garnered considerable research activity due to its key applications in quantum networking and optical communications. This paper studies the single photon routing scheme in many-emitter disordered chiral waveguide quantum electrodynamics (wQED) ladders. The wQED ladder consists of two one-dimensional lossless waveguides simultaneously and chirally coupled with a chain of dipole-dipole interacting two-level quantum emitters (QEs) or atoms. In particular, we analyze how a departure from the periodic placement of the QEs due to temperature-induced position disorder can impact the routing probability. This involves analyzing how the interplay between the collective atomic effects originating from the dipole-dipole interaction and disorder in the atomic location leading to single-photon localization can change the routing probabilities. As for some key results, we find that the routing probability exhibits a considerable improvement (more than $90\%$ value) for periodic and disordered wQED ladders when considering lattices consisting of twenty QEs. This robustness of collective effects against spontaneous emission loss and weak disorders is further confirmed by examining the routing efficiency and localization length for up to twenty QE chains. These results may find applications in quantum networking and distributed quantum computing under the realistic conditions of imperfect emitter trappings.