Hexapartite entanglement in an above-threshold Optical Parametric Oscillator

TL;DR

This paper demonstrates the generation of complex hexapartite entanglement among six optical modes using an above-threshold optical parametric oscillator, with potential applications in multicolor quantum networks.

Contribution

It provides both theoretical and experimental evidence of generating and controlling large-scale entanglement in optical modes via an OPO above threshold.

Findings

Successful generation of hexapartite entanglement among six modes

Entanglement structure controlled by pump power

Potential for linking different frequency nodes in quantum networks

Abstract

We demonstrate, theoretically and experimentally, the generation of hexapartite modal entanglement by the optical parametric oscillator (OPO) operating above the oscillation threshold. We show that the OPO generates a rich structure of entanglement among sets of six optical sideband modes interacting through the non-linear crystal. The class of quantum states thus produced can be controlled by a single parameter, the power of the external laser that pumps the system. Our platform allows for the generation of massive entanglement among many optical modes with well defined but vastly different frequencies, potentially bridging nodes of a multicolor quantum network.