Dutch research brings quantum computer a step closer

31 October 2006

Dutch researchers have produced a detailed proposal for the possible realisation of a quantum computer. That is the outcome of a PIONIER research project 'Van wervelpatronen to kwantumrekenen' [From vortex patterns to quantum computation] under the leadership of the Amsterdam professor Kareljan Schoutens. The results of this study have just been published in the Annals of Physics.

There is considerable interest in research into quantum computers as these can perform certain calculations far faster than computers without quantum mechanics. In quantum mechanics particles can simultaneously be found in several different states as it were. As a result of this a quantum bit can be both 0 and 1. This makes a new method of computation, quantum computation, possible.

In their article, Kareljan Schoutens and his colleague Eddy Ardonne describe a scenario for quantum computation using a so-called quantum Hall state that they introduced in 1999. According to the researchers, by manipulating the electrons in that system it is, in principle, possible to perform all of the logical operations needed for a quantum computer. A further advantage, according to them, is that the 'leaking away' of quantum information, a recurring problem in proposals for a quantum computer, is avoided as much as possible.

Ultracold gasses

Quantum Hall states occur in systems where electrons can freely move at the interface between two semiconductors, in the presence of a strong magnetic field. They exist in various forms. In the proposed variant that makes quantum computation possible, the electrons form pairs, as also happens in a superconductor. It is theoretically predicted that quantum Hall states can also occur in ultracold gasses that are rapidly rotated. Schoutens's group has detailed the scenario considered to be most promising for an experimental testing of this idea.

Kareljan Schoutens is professor of Theoretical Physics at the Universiteit van Amsterdam. Eddy Ardonne gained his doctorate four years ago for research within this PIONIER project. He now works at a special Microsoft research group for topological quantum computation. Their research was funded by a PIONIER subsidy from the NWO Division for the Physical Sciences. PIONIER started in 1999 and was the predecessor of the Vici round of the Innovational Research Incentive Scheme.

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For further information please contact:

• Prof. Kareljan Schoutens (Universiteit van Amsterdam)
• 31 20 525 5664, kjs@science.uva.nl
• A summary of 'Wave functions for topological quantum registers' for the scientific journal Annals of Physics can be obtained from www.sciencedirect.com from which the full article can also be requested. A printed version will be published later.