Hybrid photonic entanglement: Realization, characterization and applications

TL;DR

This paper demonstrates a method to generate and characterize hybrid photonic entanglement between different degrees of freedom of photon pairs, with potential applications in optical quantum networks.

Contribution

It introduces a general approach using a quantum disentanglement eraser to create tunable hybrid entanglement between photon degrees of freedom.

Findings

Successfully generated hybrid entanglement between momentum and polarization.

Extended setup produces qubit-qudit hybrid entangled states.

Discussed advantages for optical quantum networks.

Abstract

We show that the quantum disentanglement eraser implemented on a two-photon system from parametric down-conversion is a general method to create hybrid photonic entanglement, namely the entanglement between different degrees of freedom of the photon pair. To demonstrate this, we generate and characterize a source with tunable degree of hybrid entanglement between two qubits, one encoded in the transverse momentum and position of a photon, and the other in the polarization of its partner. In addition, we show that a simple extension of our setup enables the generation of two-photon qubit-qudit hybrid entangled states. Finally, we discuss the advantages that this type of entanglement can bring for an optical quantum network.