News in Science

Researchers claim quantum breakthrough

Giant leap Researchers say they have designed a tiny crystal that acts like a quantum computer so powerful it would take a computer the size of the known universe to match it.

Details of the crystal, which is made up of just 300 atoms, are published today in the journal Nature.

"Quantum computing is a kind of information science that is based on the notion that if one performs computations in a fundamentally different way than the way your classical desktop computer works," says study co-author University of Sydney's Dr Michael Biercuk.

"There's a huge potential to solve a variety of problems that are very, very hard or near impossible for standard computer."

The crystal simulator uses a property of quantum mechanics called superposition, where a quantum particle appears to be in two distinct states at the same time. This means the particle, known as a qubit, can be used to solve two equations simultaneously.

As the number of qubits increase, the number or states increases exponentially. For example, 2 qubits can simultaneously be in 4 states, 3 qubits in 8 states: 2 to the power of n states for n qubits.

Outstrips classical computers

According to Biercuk, the computing power of the 300-atom crystal simulator far outstrips the capacity of today's classical computer.

"It turns out that that computer would need to be the size of the known universe - which is clearly something that's not possible to achieve," he says.

Experts believe quantum computing is moving to a stage where it is so far out in front and performing such complex tasks it will be difficult to check if it is working accurately.

"They're not easily checked by a classical computer which opens a whole variety of problems," says Biercuk.

And he adds that there is still plenty of work to be done before quantum computers start appearing on desks in homes and offices.

"The central element is something like a millimetre in diameter, 300 atoms that are suspended in space," says Biercuk.

"But of course everything depends on a huge amount of technical infrastructure around it. There are vacuum chambers and pumps and lasers, and all of that takes up something like a room."