Quantum entanglement between a single photon and a trillion rubidium atoms

A group of researchers from the Faculty of Physics at the University of Warsaw has shed new light on the famous paradox of Einstein, Podolsky and Rosen after 80 years. They created a multidimensional entangled state of a single photon and a trillion hot rubidium atoms, and stored this hybrid entanglement in the laboratory for several microseconds. The research has been published in Optica.