MIT News February 15, 2018
A team of researchers in the US (MIT, Harvard University, Princeton University, NITS, University of Chicago) has observed groups of three photons interacting and, in effect, sticking together to form a completely new kind of photonic matter. In controlled experiments, the researchers found that when they shone a very weak laser beam through a dense cloud of ultracold rubidium atoms, rather than exiting the cloud as single, randomly spaced photons, the photons bound together in pairs or triplets, suggesting some kind of interaction — in this case, attraction — taking place among them. According to the researchers, if photons can influence one another, then if they can be entangled, it is possible to distribute quantum information in an interesting and useful way… read more. TECHNICAL ARTICLE
Scientists at MIT, Harvard University, and elsewhere have now demonstrated that photons can be made to interact. Image: Christine Daniloff/MIT