Thursday, August 19, 2004
Beam me across the Danube, Scotty!
The BBC is reporting that physicists have achieved a breakthrough in long-distance teleportation by tranferring key properties of light particles 600m across the Danube in Austria.
Researchers from the University of Vienna and the Austrian Academy of Science used an 800m-long optical fibre fed through a public sewer system tunnel to connect labs on opposite sides of the River Danube. The link establishes a channel between the labs, dubbed Alice and Bob. This enables the properties, or "quantum states", of light particles to be transferred between the sender (Alice) and the receiver (Bob).
Quantum teleportation relies on an aspect of physics known as "entanglement"; whereby the properties of two particles can be tied together even when they are far apart. Einstein called it "spooky action at a distance". The Nature study used an experimental method in which Alice performs a joint measurement on one photon in the entangled pair and on an "input" photon. As a result of this measurement, Bob transforms the quantum state of the other photon in the entangled pair into that of the "input" photon.
The researchers were able to teleport three distinct polarisation states between Alice and Bob via the fibre-optic cable through the tunnel. The significance of this research was that it took place under "real world" conditions. "The really interesting question for us was whether we could do this outside a lab setting, in the environment used for today's fibre-optic communications," co-author Rupert Ursin of the University of Vienna told BBC News Online.
Researchers from the University of Vienna and the Austrian Academy of Science used an 800m-long optical fibre fed through a public sewer system tunnel to connect labs on opposite sides of the River Danube. The link establishes a channel between the labs, dubbed Alice and Bob. This enables the properties, or "quantum states", of light particles to be transferred between the sender (Alice) and the receiver (Bob).
Quantum teleportation relies on an aspect of physics known as "entanglement"; whereby the properties of two particles can be tied together even when they are far apart. Einstein called it "spooky action at a distance". The Nature study used an experimental method in which Alice performs a joint measurement on one photon in the entangled pair and on an "input" photon. As a result of this measurement, Bob transforms the quantum state of the other photon in the entangled pair into that of the "input" photon.
The researchers were able to teleport three distinct polarisation states between Alice and Bob via the fibre-optic cable through the tunnel. The significance of this research was that it took place under "real world" conditions. "The really interesting question for us was whether we could do this outside a lab setting, in the environment used for today's fibre-optic communications," co-author Rupert Ursin of the University of Vienna told BBC News Online.
