Australia is in a 'wonderfully competitive position' to develop the next great leap forward in computation, the quantum computer, according to a University of Queensland researcher.
'The University of Queensland is extremely well placed with the University of New South Wales and industry partners to become a world-class centre in quantum computing,' head of the University's Centre for Laser Science Professor Gerard Milburn said.
'We have a winning proposal so that Australia can build these computers rather than selling the ideas overseas and watching other people profit.
'It's so early in the game that individuals with ingenuity who are given resources to pursue good ideas have the same chances for success as the big multi-nationals.'
Professor Milburn, who wrote his first research paper on quantum computers in 1988, heads a UQ research team including master of science student and University medallist Gil Toombes and Australian Research Council postdoctoral research fellow Dr Bill Munro.
The group is undertaking the theoretical modelling and detailed computation required for a quantum computer being developed by Dr Bruce Kane at the Semiconductor Nanofabrication Facility at UNSW, directed by Professor Robert Clark.
Professor Milburn believes the new design to be the most promising candidate yet for a quantum computer. The prototype is being developed with strategic funding, including support from the Australian Research Council and the University of Queensland.
However, it may be some years before these computers reach the office desk top.
'At least $4 million is needed to develop the new technology, and $11 million to significantly advance the project, but the commercial value of the intellectual property to industry partners will significantly outweigh this initial outlay,' he said.
'An ordinary computer is just a collection of switches - which can be in 'on' or 'off' positions. In quantum computing, individual atoms essentially become the switches.'
While conventional digital computers process information encoded in bits, quantum computers process information encoded in quantum states. The proposed Kane computer reported in Nature magazine in May is a quantum-mechanical computer which encodes information onto the nuclear spins of donor atoms in silicon electronic devices.
It is likely that the new computer will contain an internal refrigerator to keep individual atoms stable and very cold, at about one tenth of a degree of absolute zero.
Professor Milburn said the idea for a quantum computer emerged in the early 1980s, when scientists realised that as engineers tried to pack ever more logic gates and other circuit elements onto silicon chips, they would eventually reach a point where the pieces were so small that they were made out of only a handful of atoms.
And this is where scientists saw a problem. At the atomic scale, matter obeys the rules of quantum mechanics, which are quite different from the rules regulating the properties of conventional logic gates. The unpredictability of matter at this level raised the question of whether some new kind of computer could be based on quantum (atom-sized) principles.
The late physicist Richard Feynman of the California Institute of Technology produced an abstract model in 1985 which showed in principle how a quantum system could be developed.
In 1994 Peter Shor, a computer scientist at AT&T's Bell Laboratories in New Jersey, devised the first quantum computer algorithm with powerful applications.
Professor Milburn said interest in quantum computers had grown since it was recognised that quantum computers can, in principle, solve certain hard problems more quickly than conventional computers. An example of a hard problem is factoring - finding the prime numbers of a composite number. For example, the prime numbers of 15 are three and five.
The difficulty escalates sharply as the number of digits increases. Currently, with the best computers and algorithms, it is only possible to find the prime factors of a 130-digit number in a few months.
Quantum computers, by exploiting properties of quantum information, make many attempts to solve hard problems at the same time, speeding up the process considerably.
'Quantum computers will allow us to do calculations within a matter of seconds which now take weeks to achieve, ' he said.
Professor Milburn said the rapid growth of Internet commercial transactions and the importance of privacy protection had led the U.S. national security agency to take a 'deep interest' in quantum computers.
Prime factoring is a key method of encrypting data used by Governments, banks and other fields of Internet commerce. This method relies on the extreme difficulty of factorising very large numbers. Quantum computers raise the possibility that people can more easily crack the secret transactions of governments, the armed forces and the banks.
Professor Milburn said quantum computers were more susceptible to error than conventional digital computers, as quantum systems interacted with their surroundings, causing stored information to decay. However, research advances had shown that quantum error correction was possible. Detailed theoretical models were needed to fix or mitigate these errors.
Professor Milburn has written a new book on quantum computers, The Feynman Processor - an Introduction to Quantum Computing, released by Allen and Unwin in Australia on June 1. The book is part of the Frontiers of Science series presenting Australian science to the public.
The University of Queensland group also has a 'finger in the pie' of two other quantum computer technologies. The University currently has a strong collaboration with a research group at Los Alamos, U.S., on ion-trapping quantum computers.
UQ PhD student Sara Schneider is studying quantum computer equipment at Los Alamos, developing theories to understand their mechanisms, and tweaking algorithms. The work is funded by a collaborative Australian Research Council international research grant.
A third technology variation, nuclear magnetic resonance computing, has been developed, and Professor Milburn said the University of Queensland had an enormous advantage with Australia's largest and most well-equipped Centre for Magnetic Resonance. He has begun discussions with CMR director Professor David Doddrell to begin this collaboration.
Media: For further information, contact Professor Milburn, telephone 07 3365 3405, email: milburn@physics.uq.edu.au
