Circumventing defective components in linear optical interferometers

TL;DR

This paper introduces a method to bypass defective components in linear optical interferometers, enabling the construction of functional quantum optical systems despite high defect rates, thus advancing the feasibility of quantum advantage with linear optics.

Contribution

It presents a novel approach to use defective linear optical components as smaller universal interferometers, tolerating high defect rates and improving scalability.

Findings

Method tolerates high defect rates in optical components

Enables use of defective components as smaller interferometers

Brings practical quantum advantage closer to reality

Abstract

A crucial challenge to the scaling up of linear optical interferometers is the presence of defective optical components resulting from inevitable imperfections in fabrication and packaging. This work presents a method for circumventing such defective components including lossy modes and unresponsive phase shifters and beam-splitters. The method allows for using universal linear optical interferometers with such defects as smaller universal interferometers. The method presented here tolerates remarkably high defect rates in constructing linear optical interferometers, thus bringing closer to reality the possibility of obtaining quantum advantage with linear optics.