Non-classicality of bright GHZ-like radiation of an optical parametric source

TL;DR

This paper investigates bright GHZ-like entangled photon emissions from optical parametric sources, introducing a method to analyze their non-classical properties despite complex higher-order emissions.

Contribution

It presents a novel approach to generate and analyze bright GHZ-like states involving multiple entangled photon triples, overcoming technical challenges in their theoretical description.

Findings

Demonstrates the feasibility of bright GHZ-like emissions with higher-order photon triples.

Introduces a Pade approximation method to analyze non-classicality of complex entangled states.

Provides a framework for studying non-classical properties of generalized GHZ states.

Abstract

With the emerging possibility to obtain emissions of triples of GHZ-entangled photons via a direct parametric generation we study here bright emissions of this kind which involve higher order emissions of two triples, three triples, etc. Such states would constitute a natural generalization of the four mode (two beams plus polarization) squeezed vacuum. We have three beam process of emission generalized bright GHZ states, which a are superpositions of one, two, three, and so on GHZ entangled triples of photons. We show how to avoid technical difficulties related with straight ahead generalization of the usual description of parametric down conversion. Using Pade approximation we turn first terms of the non-converging perturbation expansion into elements of conversing series. This allows us to study non-classicality of the new bright generalized GHZ states.