Intelligent Machines

Japanese scientists make key step toward developing quantum computer

May 3, 2007

TOKYO (AP) – Scientists in Japan have made a key step toward the development of a quantum computer – a still largely hypothetical device that would be dramatically more powerful than today’s supercomputers – according to Japanese electronics giant NEC Corp.

In what they claimed was a world first, researchers at NEC and the state-funded Institute of Physical and Chemical Research successfully demonstrated a circuit that can control the state of a pair of elemental particles and how strongly they interact with one another.

Being able to control these particles – called ”qubits” – in this fashion may help scientists to build a quantum computer, though actually developing one still lays many years in the future, research team member Yasunobu Nakamura said Wednesday.

”These results do not change the fact that there are still many difficulties to be resolved,” Nakamura said.

The NEC team, led by Jaw-Shen Tsai, published their results Thursday in the American science journal ”Science.”

Tsai’s team has already made several major steps toward developing a quantum computer, including getting elementary particles to interact with one another and controlling their ability to seemingly be in many places at the same time, a concept known as ”superposition” in quantum physics.

Quantum physics is the study of the behavior of subatomic particles, such as electrons.

Many scientists believe quantum computing – which takes advantage of the superposition concept – promises to solve certain factoring, simulation and other intensive problems faster than today’s machines that rely on classical physics.

Earlier this year, Canadian company D-Wave Systems Inc. demonstrated a machine it claims uses quantum mechanics to solve certain types of problems. However, independent quantum physics researchers have said they are dubious of some of the company’s claims as its findings have yet to be submitted for peer review – a standard step for gaining acceptance in scientific circles.

D-Wave itself acknowledged that even it isn’t entirely sure the machine – which the company claims to be the ”world’s first commercial quantum computer” – is performing true quantum calculations.