Classical model for measurements of an entanglement witness

TL;DR

This paper introduces a classical model that mimics the measurement process of an entanglement witness, aligning well with quantum results and experimental data, highlighting the role of contextuality in such measurements.

Contribution

The paper presents a classical analog for joint and local measurements of an entanglement witness, demonstrating its effectiveness through simulations and comparison with quantum experiments.

Findings

Classical model reproduces quantum measurement results

Excellent agreement between simulations and experiments

Model exhibits contextuality due to postselection

Abstract

We describe a classical model that may serve as an analog for joint and local measurements of an entanglement witness. The analogous experimental procedure and data analysis protocol of the model follow those of a previous experiment to measure an entanglement witness with polarized photons prepared in a mixed state [Phys. Rev. Lett. \textbf{91}, 227901 (2003)]. Numerical simulations show excellent agreement with both experimental results and quantum-mechanical predictions. This agreement is made possible by the fact that the model exhibits contextuality due to the postselection of coincident detection events.