New computer hits quantum speeds

simple computer that marries the mind-boggling computing power of quantum mechanics with the ease of manipulating light has been built by researchers at the University. The device proves that a specific quirk of atoms, which lets scientists conduct huge computations almost instantly, can be perfectly mimicked by light, which is much more practical to control than individual atoms.

The result could be a computer that performs some tasks a billion times faster than today's supercomputers, using relatively simple technology that's already well understood. The research behind the device was presented at the Lasers and Electro-Optics Quantum Electronics and Laser Science conference in Baltimore, Maryland.

The device mimics quantum interference, an important property that makes quantum computers exponentially faster at tasks such as breaking encryption codes or searching huge databases. Instead of interference, conventional computers use particles called electrons to perform tasks sequentially, like a librarian looking for a book by inspecting the entire library one volume at a time. Interference essentially allows you to make clones of that librarian--one librarian for every book--and set them all loose at once. The new device proves that using light interference is just as effective as quantum interference in retrieving items from a database.

"There's a big push to explore information processing based on quantum mechanics," says Ian Walmsley, professor of optics at the University, who led the team that invented the device. "You can do things with quantum mechanics that are impossible on classical machines. What we've shown here is that if you have a quantum computer that is 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."

What makes the device so attractive is that it is so simple in comparison to quantum computers. Engineers have had decades of experience precisely manipulating light, and all the concepts in the device are based on well-known, 19th-century classical physics. But, as Walmsley points out, the technology to carry out the experiment only became available in the last 10 years. "In effect, we are leveraging new physics on the back of optical technology. It's a synergy that is particularly easy at Rochester and illustrates the close links between basic science and engineering."

The research was funded by Department of Defense through the Center for Quantum Information.

Maintained by University Public Relations
Please send your comments and suggestions to:
Public Relations.