ACADEMIA

A calculation which would take a fast modern computer a million years will take a quantum computer an instant. Australian researchers are part of a world-wide push to develop the first practical solid state quantum computer - a device that uses single atoms to store its memory and perform its calculations. As part of this effort, in close collaboration with colleagues at the University of New South Wales, researchers in Melbourne have devised a method of placing single phosphorus atoms in a block of ultra-pure silicon, so that they can be used as components in the tiny device. "Smallness is not the only goal," says Professor David Jamieson of the School of Physics at Melbourne University. "We are also after a computer that operates using the laws of quantum physics" "This could result in a computer that performs some operations blindingly fast. But quantum laws only operate at very small scales," he says. "Quantum laws allow vastly complex calculations to be performed at speeds that are unthinkable with conventional computers. "Today's conventional computers, however powerful, still operate according to the laws of classical physics," he says. Professor Jamieson says that colleagues at the University of Queensland are researching the design of a quantum computer based on light particles (photonics) rather than the solid state design of the University of Melbourne/University of New South Wales team. "We are exploring the capabilities of constructing qubits for a practical quantum computer device" he says. "A qubit is the name for a computer 'memory bit' which operates by the laws of quantum physics." "Our immediate and challenging goal is to create a working 2 qubit device in silicon that is compatible with conventional silicon chip technology," he says. "Research teams overseas have already made great progress towards quantum computer devices, but using alternative technologies." Professor Jamieson says that the quantum computer is 'massively parallel', which means that it can perform a massive number of tasks at the same time. This would enable it to search extremely large sets of data, doing tasks in an instant which would take a conventional computer thousands or millions of times longer. Applications for a quantum computer could include rapidly searching the human genome data base, with its many trillions of pieces of data, looking for a specific sequence, and most importantly, says Professor Jamieson, to model the quantum systems which 'drive' the entire universe. "Most of the fundamental physics that shapes our Universe are based on the rules of quantum mechanics," he says. Another use for quantum computing is in the field of cryptology where a quantum code, known as Shor's Algorithm may be used to efficiently find the prime number factors of large numbers. Professor Jamieson works on these problems as a member of the Australian Research Council Centre of Excellence for Quantum Computer Technology that now involves more than 90 Australian research workers. He is one of more than 160 eminent Australian scientists available for interview about their work and science in general during National Science Week. For details visit: www.scienceweek.info.au