Post by Chicago Astronomer - Astro Joe on Aug 21, 2004 1:00:46 GMT -6
Teleportation goes long distance
Scientists have now "beamed" particles of light over a large distance. The Transporter room looks a bit closer now.
---------------------------------------------------------------------
Properties were teleported from one photon to another
Physicists have carried out successful teleportation with particles of light over a distance of 600m across the River Danube in Austria.
Long distance teleportation is crucial if dreams of superfast quantum computing are to be realised.
When physicists say "teleportation", they are describing the transfer of key properties from one particle to another without a physical link.
The team has published its findings in the academic journal Nature.
The really interesting question for us was whether we could do this outside a lab setting
Rupert Ursin, University of Vienna
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).
In the computers of tomorrow, this information would form the qubits (the quantum form of the digital bits 1 and 0) of data processing through the machines.
The Austrian team encoded their qubits using a property of light particles, also called photons, known as polarisation. This property describes the direction in which they oscillate.
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".
More here from the BBC: news.bbc.co.uk/2/hi/science/nature/3576594.stm