Eugen Leitl wrote:

On Thu, Jan 20, 2005 at 10:47:38AM -0500, Trei, Peter wrote:

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I've actually seen these devices in operation. The thing that impressed me most was that the path need not be a single fiber from end to end - you can maintain quantum state across a switchable fiber junction. This means

Very impressive. If they manage to keep the entanglement all the way up to LEO by line of sight it would be even more impressive (anyone thinks this can be done at all?)

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you are no longer limited to a single pair of boxes talking to each other.

At the moment, the practical limit in fiber is around 150 km Getting to LEO is a *lot* harder - remember, you're throwing and catching one photon at a time - a beam that spreads wider than your detector is usually going to miss the detector. Peter Trei