Teleportation Gets a Boost

saavyone writes to tell us Yahoo! News is reporting that while teleportation may not quite be a reality yet a team of Danish scientists have raised the bar on this line of research. From the article: "The experiment involved for the first time a macroscopic atomic object containing thousands of billions of atoms. They also teleported the information a distance of half a meter but believe it can be extended further. 'Teleportation between two single atoms had been done two years ago by two teams but this was done at a distance of a fraction of a millimeter,' Polzik, of the Danish National Research Foundation Center for Quantum Optics, explained. 'Our method allows teleportation to be taken over longer distances because it involves light as the carrier of entanglement,' he added."

Comments

Re:Please...

[tloh]

That yahoo article isn't really saying much at all. There is almost no real information on how they did it. Scientific American has a much more detailed description. http://www.sciam.com/article.cfm?chanID=sa003&arti cleID=000E9691-0261-1524-826183414B7F0000

In taking the next step, Eugene Polzik and his colleagues at the Niels Bohr Institute in Copenhagen shined a strong laser beam onto a cloud of room-temperature cesium atoms whose spins were all pointing in the same direction and fluctuating according to their given quantum state. The laser became entangled with the collective spin of the cloud, meaning that the quantum states of laser and gas shared the same amplitude but had opposite phases. The goal was to transfer, or teleport, the quantum state of a second light beam onto the cloud.

To do so, the group mixed a second, weaker laser pulse with the strong laser and split the superimposed beams into two arms. A detector in one arm measured the sum of the beams' amplitudes and a detector in the second arm measured the difference between their phases. Neither measurement disturbed the delicate entangled state between the light and cesium. But the researchers could use the results to apply a precise magnetic field to the cesium vapor that effectively canceled out the ensemble's original spin state and replaced it with one that corresponded to the polarization of the weak pulse, as they report in the 5 October Nature.