Experimental identification of non-classicality of noisy twin beams and other related two-mode states

TL;DR

This paper evaluates various non-classicality criteria for noisy twin beams and two-mode states, comparing their effectiveness against exact entanglement measures, highlighting their strengths and limitations in experimental detection.

Contribution

It systematically assesses the performance of intensity moment inequalities in detecting non-classicality in noisy two-mode states, providing insights into their reliability and limitations.

Findings

Non-classicality of noisy twin beams is always detected by the criteria.

Not all non-classical states after a beam splitter are identified by these criteria.

Criteria are effective but have limitations in certain non-classical states.

Abstract

Different non-classicality criteria expressed in the form of inequalities among intensity moments and elements of photon-number distributions are applied to noisy twin beams and other two-mode states obtained from a twin beam by using a beam splitter. Their performance in revealing the non-classicality is judged in comparison with the exact results provided by suitable entanglement and local non-classicality quantifiers. Whereas the non-classicality of noisy twin beams is always revealed by these criteria, not all the nonclassical states obtained at the output of the beam splitter can be identified by these experimentally easily reachable criteria.