Saturday, March 29, 2008

Entanglement

"Entanglement is one of the most puzzling phenomena in quantum mechanics, and also one of the most difficult to illustrate, which could help explain why this image of entangled photons has proved so popular. The photograph was created by Paul Kwiat and Michael Reck at the University of Innsbruck in Austria in 1995."

Entanglement or the creation of linked states for photons, electrons and even clouds of atoms, gives rise to the power of quantum computing because the superposition of states of entangled entities enables quantum systems to parallel process any problem (ray tracing, factoring numbers, database search, decryption and last but not least, creating reality itself) at speeds that go beyond calculation. The problem with creating this mother of all computers is decoherence whereby the delicate superposition of said linked entities existing at multiple states at the same time (spin up/down etc., etc.) collapses when "touched" by the most subtle of influences of the "real world" - until now.

"The team generated pairs of photons (in a silicon chip) which each encoded a quantum bit or qubit of information. They coupled these photons into and out of the controlled-NOT chip using optical fibres. By measuring the output of the device they confirmed high-fidelity operation.

In the experimental characterisation of the quantum chips the researchers also proved that one of the strangest phenomena of the quantum world, namely "quantum entanglement", was achieved on-chip. Quantum entanglement of two particles means that the state of either of the particles is not defined, but only their collective state."


When this tech is combined with findings from The Ames Lab, UCSB and Microsoft Station, interesting things could begin to happen. "researchers were able to manipulate the N-V centers interacting with an environment of nitrogen spins in a piece of diamond. Amazingly, the physicists were able to tune and adjust the environmental interference extremely well, accessing surprisingly different regimes of decoherence in a single system. The scientists showed that the degree of interaction between the qubit and the interfering environment could be regulated by applying a moderate magnetic field.

"This is your last chance. After this, there is no turning back. You take the blue pill -- the story ends, you wake up in your bed and believe whatever you want to believe. You take the red pill -- you stay in Wonderland and I show you how deep the rabbit-hole goes."

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