14 March 2007
Physicists in France are the first to watch single photons appear spontaneously, live a brief life, and then vanish into thin air. The experiment is the best realization so far of "quantum non-demolition" (QND) measurements on single photons, whereby the presence of a photon is determined without destroying it. As well as providing an elegant demonstration of quantum mechanics, the researchers also believe that the technique could be exploited in quantum information systems (Nature 446 297).
