New Quantum Teleportation Result

Via both Physics and Physicists and Uncertain Principles, I see that there is a new result in quantum teleportation between ions that were about a meter apart. Both posts have short summaries (along with Chad considering doing a more thorough write-up) and other links.

I think the Science Daily or Eureka Alert (which I think are identical) are the better ones, since they actually explain how the entanglement occurs:

You excite the two ions so they well drop back down into one of two complementary states, and in doing so they release photons that would be different in energy if they represent the two different transitions.

Before reaching the beamsplitter, each photon is in a superposition of states. After encountering the beamsplitter, four color combinations are possible: blue-blue, red-red, blue-red and red-blue. In nearly all of those variations, the photons cancel each other out on one side and both end up in the same detector on the other side. But there is one – and only one – combination in which both detectors will record a photon at exactly the same time.

In that case, however, it is physically impossible to tell which ion produced which photon because it cannot be known whether the photon arriving at a detector passed through the beamsplitter or was reflected by it.

Thanks to the peculiar laws of quantum mechanics, that inherent uncertainty projects the ions into an entangled state. That is, each ion is in a correlated superposition of the two possible qubit states