麻豆视频

7 January 2010

physicists and chemists have teamed up to build a quantum computer that could have profound implications for wider science.

Professor Andrew White and colleagues from 麻豆视频鈥檚 , teamed up with researchers from Harvard University, led by Professor Al谩n Aspuru-Guzik, to tackle the problem of applying quantum mechanics to fields such as chemistry and biology.

鈥淧hysicists have a problem,鈥 Professor White said.

鈥淭hey have an outstandingly successful theory of nature at the small scale 鈥 quantum mechanics 鈥 but have been unable to apply it exactly to situations more complicated than, say, four or five atoms.

鈥淏ut now we have done exactly that by building a small quantum computer and used it to calculate the precise energy of molecular hydrogen."

This groundbreaking approach to molecular simulations could have profound implications not just for chemistry, but also for a range of fields from cryptography to materials science.

The work, published this week in , saw Professor White鈥檚 team assemble the physical computer and run the experiments, while Professor Aspuru-Guzik鈥檚 team coordinated experimental design and performed key calculations.

鈥淲e were the software guys and they were the hardware guys,鈥 Professor Aspuru-Guzik said.

While modern supercomputers can perform approximate simulations, increasing the complexity of these systems results in an exponential increase in computational time.

鈥淨uantum computers promise highly precise calculations while using a fraction the resources of conventional computing,鈥 he said.

鈥淭his computational power derives from the way quantum computers manipulate information. In classical computers, information is encoded in bits, that have only two values: zero and one. Quantum computers use quantum bits 鈥 qubits 鈥 that can have an infinite different number of values such as zero, or one, or zero plus one, and so on.

鈥淨uantum computers also exploit the strange phenomena of entanglement, powerful correlations between qubits that Einstein once described as 鈥榮pooky action at a distance鈥.鈥

Professor White said it would be a while before quantum computers would leave the lab and appear on desktops.

鈥淚t鈥檚 very early days for quantum technology,鈥 he said.

鈥淢ost quantum computer demonstrations have been limited to a handful of qubits. A colleague of mine in Canada says that any demonstration with less than ten qubits is cute but useless, which makes me think of a baby with an abacus.

鈥淗owever, Al谩n and his team at Harvard have shown that when we can build circuits of just a few hundred qubits, this will surpass the combined computing power of all the traditional computers in the world, each of which uses many billions of bits.鈥

鈥淚t took standard computing 50 years to get to this point, I鈥檓 sure we can do it in much less time than that.鈥

Professor White鈥檚 麻豆视频 co-authors on the Nature Chemistry paper were Benjamin P. Lanyon, Geoffrey G. Gillet, Michael E. Goggin, Marcelo P. Almeida, Benjamin J. Powell, and Marco Barbieri. Funding was provided by the Australian Research Council Federation Fellow and Centre of Excellence programs, and the US Army Research Office (ARO) and Intelligence Advanced Research Projects Initiative (IARPA).

Media: Professor Andrew White (0404 446 835, 07 3365 7902; int +61 4 0444 6835, +61 7 3365 7902; email: agx.white@gmail.com).