Non-Gaussian Nature and Entanglement of Spontaneous Parametric Nondegenerate Triple-Photon Generation

TL;DR

This paper demonstrates that triple-photon states from spontaneous parametric down-conversion are non-Gaussian entangled resources with stronger entanglement than two-mode squeezed states, and proposes a method to prepare tunable non-Gaussian entangled states.

Contribution

It provides a theoretical demonstration of non-Gaussian entanglement in triple-photon states and introduces a model for preparing tunable non-Gaussian entangled states.

Findings

Triple-photon states are super-Gaussian non-Gaussian entangled resources.

Entanglement in triple-photon states exceeds that of two-mode squeezed vacuum.

A model for tunable non-Gaussian entangled state preparation is proposed.

Abstract

How to prepare deterministically non-Gaussian entangled states is a fundamental question for continuous-variable quantum information technology. Here, we theoretically demonstrate through numerical methods that the triple-photon state generated by three-photon spontaneous parametric down-conversion is a pure super-Gaussian resource of non-Gaussian entanglement. Interestingly, the degree of entanglement between the modes of the triple-photon state is stronger than that corresponding to the two-mode squeezed vacuum state produced by a quadratic Hamiltonian with the same parameters. Furthermore, we propose a model to prepare two-mode non-Gaussian entangled states with tunable non-Gaussianity based on quadrature projection measurements.