NUIM Math. Physics seminar

Mark Howard  
University of California, Santa Barbara

Tight Noise Thresholds for Quantum Computation with Perfect Stabilizer Operations

Friday 18 December 2009 at 3.15 p.m.

CS1 (Computer Science Lecture Theatre 1), Callan Building, NUIM North Campus

Abstract:

We examine the transition, as the amount of noise is increased, from a system that has the power to perform quantum computation to a system that is no better than a classical computer. Implementing a quantum computation requires the ability to perform, at will, a number of basic gates reliably, and in such a way that errors in the gates do not propagate around the circuit and ruin the computation. One set of operations that regularly crop up in quantum computation is the set of stabilizer operations, and methods are known which allow implementation of stabilizer operations in a fault-tolerant (i.e. non-error-spreading) manner. Circuits using only these stabilizer operations are no more powerful than classical computation though, so we require the ability to perform any other gate that is not a stabilizer operation. We examine closely the effect of noise on this additional gate and see that, for every possible single-qubit gate, there exists an exact noise rate, above which the overall computation is effectively classical, and below which we have the full power of quantum computation.

All are welcome. Tea/coffee and biscuits to follow. For directions to the Dept. please check http://www.thphys.nuim.ie/map.php