EXPERIMENTAL ENTANGLEMENT RESTORATION ON NOISY CHANNELS BY MEASURING ENVIRONMENT
Eleonora Nagali, Fabio Sciarrino, F. De Martini, Miroslav Gavenda, Radim Filip · International Journal of Quantum Information · 2009
In the last years, different procedures have been developed in order to recover entanglement after propagation over a noisy channel. However, above a certain amount of noise, entanglement is completely lost. In this case the channel is called "entanglement-breaking" and any multi-copy distillation methods cannot help to reveal even a bit of entanglement. We report the experimental realization of a new protocol which restores entanglement from a single photon entanglement-breaking channel by measuring the information leaking out into the environment. Such restoration entanglement procedure provides new elements to overcome decoherence effects, a subject of renowed interest in quantum communication in the last decade.