[ExI] Topological Quantum Computer

[john clark]

A new type of particle (a quasi particle actually) called a  "Majorana fermion" has just been found, it is thought that they are non-abelian, if so then a particle exchange operation between two of them would be  non-commutative; the particles (called Anyons) would in a sense remember where they have been and you could tie their world lines into a knot. This could have big implications for a new type of quantum computer called a "Topological Quantum Computer" because Anyons would be MUCH less sensitive to quantum decoherence than normal matter and decoherence is the main obstacle to making a practical quantum computer. It's easy to jolt a string into a new position but its far more unlikely that you could jolt a string in just the right way to untie a knot in it, and a Topological Quantum Computer uses the knots in the world line of those  Majorana Anyons to do its quantum computing. These quasi particles form on the 2 dimensional surface of a
 topological insulator, a substance that is conductive on its surface but not in it's interior, if it is cooled to very close to absolute zero and placed in a powerful magnetic field. 

Incidentally some think Dark Matter is also some sort of  Majorana fermion, although in this case it would be real particles not quasi particles as in the above, but quasi particles would work fine in a computer.

Take a look at the breaking news:

http://prl.aps.org/abstract/PRL/v108/i13/e130501


  John K Clark


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