Continuous variables triple-photon states quantum entanglement

TL;DR

This paper studies quantum entanglement in three-photon states generated via third-order nonlinear optical interactions, revealing conditions for genuine triple-photon entanglement and its dependence on seeding levels.

Contribution

It demonstrates the presence of genuine triple-photon entanglement in fully seeded triple-photon generation, contrasting with the absence of entanglement in spontaneous cases.

Findings

No entanglement in spontaneous triple-photon generation.

Genuine triple-photon entanglement appears with seeding.

Entanglement efficiency increases with seeding level.

Abstract

We investigate the quantum entanglement of the three modes associated with the three-photon states obtained by triple-photon generation in a phase-matched third-order nonlinear optical interaction. Although the second order processes have been extensively dealt with, there is no direct analogy between the second and third-order mechanisms. We show for example the absence of quantum entanglement between the quadratures of the three modes in the case of spontaneous parametric triple-photon generation. However, we show that genuine triple-photon entanglement is obtained in the fully seeded case, and its efficiency increases with the seeding level.