Experimental quantum non-Gaussian coincidences of entangled photons

TL;DR

This paper demonstrates the first experimental verification of quantum non-Gaussian coincidences in entangled photon pairs from a quantum dot, highlighting their potential for advanced quantum technologies.

Contribution

It provides the first conclusive experimental test of quantum non-Gaussian coincidences in entangled photons from a quantum dot, surpassing parametric processes in reducing errors.

Findings

CHSH-Bell factor of 2.328±0.004 indicating strong entanglement

Quantum non-Gaussian depth up to 8.08 dB (unheralded) and 19.06 dB (heralded)

Certifies quantum non-Gaussianity's relevance for quantum sensing, communication, and computation

Abstract

Quantum non-Gaussianity, a more potent and highly useful form of nonclassicality, excludes all convex mixtures of Gaussian states and Gaussian parametric processes generating them. Here, for the first time, we conclusively test quantum non-Gaussian coincidences of entangled photon pairs with the CHSH-Bell factor $S=2.328\pm0.004$ from a single quantum dot with a depth up to $0.94\pm 0.02$ dB. Such deterministically generated photon pairs fundamentally overcome parametric processes by reducing crucial multiphoton errors. For the quantum non-Gaussian depth of the unheralded (heralded) single-photon state, we achieve the value of $8.08\pm0.05$ dB ($19.06\pm0.29$ dB). Our work experimentally certifies the exclusive quantum non-Gaussianity properties highly relevant for optical sensing, communication and computation.