IBM develops quantum computer

Reuters

NEW YORK -- International Business Machines Corp. said today it had developed the world's most advanced quantum computer, a device based on the mysterious quantum physics properties of atoms that allow them to work together as a computer's processor and memory.

IBM said the computer, which uses five atoms to work as its processor and memory, demonstrates for the first time the potential of such devices to solve certain problems at a rate remarkably faster than conventional computers. The experimental machine is considered the next step toward a new class of devices capable of superfast calculations.

``A quantum computer could eventually be used for practical purposes such as database searches -- for example searching the Web could be sped up a great deal -- but probably not for more mundane tasks such as word processing,'' said Isaac Chuang, the IBM researcher who led the team of scientists from IBM, Stanford University and the University of Calgary.

A quantum computer could also be used for cryptography, or the making and breaking of codes. This has drawn the interest of the U.S. National Security Administration and the Department of Defense, which are funding Stanford's efforts to build the quantum computer.

The current method of creating processors, which are becoming increasingly smaller and more powerful as described by an axiom known as Moore's Law, is expected to reach a barrier sometime in the next decade or so. This process, lithography, will not allow for the creation of microchips the size of molecules, prompting researchers to try to build computers by using genetic strands or developing other tiny technologies.

``Quantum computing begins where Moore's Law ends -- about the year 2020, when circuit features are predicted to be the size of atoms and molecules,'' Chuang said. ``Indeed, the basic elements of quantum computers are atoms and molecules.''

Chuang said in an interview that his team used the test quantum computer to solve a typical mathematical problem used in cryptography -- finding the period of a function. The computer was able to solve any example of the problem in one step, while a conventional computer would require repeated cycles to solve the problem.

Chuang said the experiment showed the viability of the quantum computer.

``I think this experiment shows we are on a pathway which is predictable and understandable, that quantum computers will be useful someday,'' he said.

The quantum computer is based on the spin of an electron or atomic nucleus, and the strange properties of quantum particles in which they can spin simultaneously in different directions if they are not observed.

When the spin of a particle is up, the atom can be read as a one, and the spin down can be read as a zero, corresponding to the digital ones and zeros that form the binary language of traditional computers. Such devices use transistors, which are turned on and off to represent the ones and zeros.

What makes quantum computers unique, however, is that quantum particles can also be in a state of ``superposition'' -- spinning simultaneously up and down.

It is unclear when such a computer would be commercially available.