Control of quantum transverse correlations on a four-photon system

TL;DR

This paper demonstrates experimental control over quantum correlations in a four-photon system, enabling manipulation of entangled and separable states to influence interference and diffraction patterns in quantum imaging.

Contribution

It introduces a novel experimental scheme for controlling quantum correlations in a four-photon system using a high-efficiency downconversion source and linear optics.

Findings

Controlled entangled and separable photon pairs were generated.

Quantum correlations affected interference and diffraction patterns.

The method enables manipulation of spatial quantum correlations in multi-photon systems.

Abstract

Control of spatial quantum correlations in bi-photons is one of the fundamental principles of Quantum Imaging. Up to now, experiments have been restricted to controlling the state of a single bi-photon, by using linear optical elements. In this work we demonstrate experimental control of quantum correlations in a four-photon state comprised of two pairs of photons. Our scheme is based on a high-efficiency parametric downconversion source coupled to a double slit by a variable linear optical setup, in order to obtain spatially encoded qubits. Both entangled and separable pairs have been obtained, by altering experimental parameters. We show how the correlations influence both the interference and diffraction on the double slit.