Largest Quantum Bell Test Spans Three Swiss Towns

In the Bell test, two photons from an entangled pair were sent from Geneva to Satigny and Jussy, two small towns located 18 km apart. This distance enabled the space-like separation necessary for finishing a quantum measurement in each town, which required a macroscopic mass to move. Detection of the mass’ movement was completed before information could have traveled between the two towns. Credit: D. Salart, et al.

In an attempt to rule out any kind of communication between entangled particles, physicists from the University of Geneva have sent two entangled photons traveling to different towns located 18 km apart – the longest distance for this type of quantum measurement. The distance enabled the physicists to completely finish performing their quantum measurements at each detector before any information could have time to travel between the two towns.

Source: http://www.physorg.com/preview132830327.html