Optimal photonic indistinguishability tests in multimode networks

TL;DR

This paper demonstrates that Sylvester interferometers are nearly optimal for certifying photon indistinguishability in quantum photonic experiments, with successful implementation and application to Boson Sampling.

Contribution

It introduces and experimentally validates the use of integrated Sylvester interferometers for optimal photon indistinguishability testing in multimode networks.

Findings

Sylvester interferometers are near-optimal for photon indistinguishability tests.

Successful implementation of 4 and 8 mode Sylvester interferometers.

Effective Bayesian analysis with small data sets for interference identification.

Abstract

Particle indistinguishability is at the heart of quantum statistics that regulates fundamental phenomena such as the electronic band structure of solids, Bose-Einstein condensation and superconductivity. Moreover, it is necessary in practical applications such as linear optical quantum computation and simulation, in particular for Boson Sampling devices. It is thus crucial to develop tools to certify genuine multiphoton interference between multiple sources. Here we show that so-called Sylvester interferometers are near-optimal for the task of discriminating the behaviors of distinguishable and indistinguishable photons. We report the first implementations of integrated Sylvester interferometers with 4 and 8 modes with an efficient, scalable and reliable 3D-architecture. We perform two-photon interference experiments capable of identifying indistinguishable photon behaviour with a Bayesian approach using very small data sets. Furthermore, we employ experimentally this new device for the assessment of scattershot Boson Sampling. These results open the way to the application of Sylvester interferometers for the optimal assessment of multiphoton interference experiments.