State reconstruction of a multimode twin beam using photodetection

TL;DR

This paper introduces a robust method for reconstructing the quasi-distributions of twin beams generated in spontaneous parametric down-conversion, distinguishing quantum from classical states using photocount moments and a non-classicality criterion.

Contribution

It presents a new method utilizing photocount moments to accurately reconstruct twin beam states and differentiate quantum from classical states, including a criterion for non-classicality.

Findings

The method effectively reconstructs quasi-distributions from experimental data.

It distinguishes quantum and classical states based on reconstructed distributions.

A momentum criterion for non-classicality is proposed.

Abstract

Robust and reliable method for reconstructing quasi-distributions of integrated intensities of twin beams generated in spontaneous parametric down-conversion and entangled in photon numbers is suggested. It utilizes the first and second photocount moments and minimizes the declination from experimental photocount histograms. Qualitatively different forms of quasi-distributions for quantum and classical states are suggested in the method. The transition from quantum to classical states caused by an increased detection noise is discussed. Momentum criterion for non-classicality of twin beams is suggested.