Entanglement swapping in a Franson interferometer setup

TL;DR

This paper introduces a scheme for entanglement swapping in a Franson interferometer setup, enabling nonlocal correlation transfer between frequency-entangled photon pairs from separate sources, demonstrated through specific interferometric measurements.

Contribution

It presents a novel method to swap nonlocal correlations in a Franson interferometer using two independent sources and postselection, expanding quantum entanglement manipulation techniques.

Findings

Nonlocal correlations can be swapped between photon pairs from separate sources.

Coincidence counts depend nonlocally on interferometer settings after postselection.

The scheme demonstrates potential for quantum communication and entanglement distribution.

Abstract

We propose a simple scheme to swap the non local correlations, characteristic of a Franson interferometric setup, between pairs of frequency entangled photons emitted by distinct non linear crystals in a parametric down conversion process. Our scheme consists of two distinct sources of frequency entangled photons. One photon of each pair is sent to a separate Mach - Zender interferometer while the other photons of the pairs are mixed by a beam splitter and then detected in a Ou - Mandel interferometer. For suitably postselected joint measuremetns, the photons sent at the Mach -Zender show a coincidence photocount statistics which depends non locally on the settings of the two interferometers.