Wednesday, September 5, 2012

New record in quantum teleportation

While it sounds like science fiction, it is possible to instantaneously teleport data between two places. It is one of the wonders of the quantum world, and it works with a process called quantum entanglement. Scientists have already shown that they can teleport so-called quantum states over a distance of around 100km. However, a new attempt resulted in teleportation spanning a distance of 143km, which is a new world record. By increasing the distance, we should eventually be able to create extremely fast quantum networks suitable for communication.

Before instantaneous teleportation is possible, it is necessary to 'entangle' the source material. Because the quantum world describes the behaviour of subatomic particles, they play by different rules than what we are used to. Such is the case with entanglement, which is a process that results in two subatomic particles sort of grouping together and attaining exact opposite characteristics. This entangled state is kept even if the two particles are separated. And because of something called superposition, subatomic particles do not assume a definite 'role' until they are measured.
Because of entanglement and superposition, measuring a particle at point A and assessing its characteristics will immediately have effect on the second particle of the pair. Let's, for simplicity's sake, say that scientists measure the characteristic 'up' at point A, scientists at point B will then immediately measure 'down' for the second particle. Because an action at point A modifies outcome at point B, this can be seen as teleportation of data. By using so-called quantum bits, scientists are able to send each other information by using entangled particles.

The teleportation of data across a distance of 143km was achieved by scientists working at the University of Waterloo. That is significantly longer than the previous record of around 100km. What is especially interesting is the fact that 143km is the minimal required distance for communication with satellites in low orbit. By getting satellites into the quantum network, information could be spread across the globe, paving the way for global quantum communication. This would be a lot faster than conventional networks, which rely on particles travelling at the speed of light to reach their destination.

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