Quantum-light processor may thrash supercomputers

By Richard Stenger
CNN

(CNN) -- Mimicking quantum mechanics and using laser technology, scientists have constructed the prototype of a lightning-fast computer that could render conventional supercomputers obsolete.

The new processor is expected to be capable of conducting myriad computations simultaneously, unlike traditional electron-powered ones that must trudge through number-crunching tasks in sequence.

Researchers say that by using light instead of electrons to drive the processing, the quantum computer can break encryption codes or search huge databases billions of times faster than its contemporaries.

The University of Rochester team members unveiled the demonstration machine this week, likening a conventional computer to a librarian searching for a book by inspecting the entire collection one volume at a time. The new machine, in effect, makes clones of the librarian and puts them all into the search at once.

Equally efficient

The new device imitates quantum interference, an important property that makes quantum computers exponentially faster at tasks requiring serious number crunching.

But rather than power the computations by relying on quantum "entanglements" -- mysterious subatomic groupings highly resistant to human control -- the scientists instead have used directed beams of light, which are well understood and easily manipulated.

"What we've shown here," says team-leading optics professor Ian Walmsley, "is that if you have a quantum computer based entirely on quantum interference, we can build you a computer that is equally efficient, based entirely on light interference. And light is a whole lot easier to manipulate than quantum systems."

The researchers, who receive funding from the United States Department of Defense, revealed the science behind their machine at a laser science conference in Baltimore, Maryland.