Stop, Light.

parvati writes: "The New York Times is reporting that two separate research teams, both from Cambridge, MA, have managed to slow, stop, and then reconstitute light. The ability to stop and then accurately restore a beam of light has implications for quantum computing and communication in that it may provide a mechanism to store the information coded by single photons."

Comments

Re:light stopped? Or destroyed and re-emitted...

[zCyl]

Technically, taking a quantum snapshot of a photon and then recreating it is the same thing as stopping it and restarting it. When we get down to such a level, we sacrifice the idea that a particle has an individual identity, and instead only acknowledge the existence of a set of properties for the particle. If the experiment simply resulted in light of the same frequency being emitted, then this would still be interesting as a means of optical storage, but by no means would it be as interesting from a theoretical perspective. What makes it interesting is that the imprint of the light is stored in the quantum spin states of the gas atoms, which means there is a theoretical possibility (which can't be determined too well from a nytimes article) that all the "uncertainty information" inherent in the photon is preserved across the restart. That would make this a true stopping and restarting of a photon.