Eugen Leitl wrote: > On Thu, Jan 20, 2005 at 10:47:38AM -0500, Trei, Peter wrote: > > > 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?) > > > 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