NEW YORK (Reuters) - International Business Machines Corp. (IBM.N)
said on Tuesday 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,'' said Chuang. ``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.
``Due to their small size and if they are very well isolated, they
can be spinning up and down at the same time,'' said Chuang.
This state would represent both zero and one and everything in
between. Instead of solving the problem by adding all the numbers in
order, a quantum computer would add all the numbers at the same time.
This phenomenon permits a quantum computer to have enormous power,
Chuang said. For certain types of calculations, like complex
algorithms for cryptography or searches -- a quantum computer using
several hundred more atoms in tandem would be able to perform billions
of calculations at the same time.
However, it is unclear when such a computer would be commercially
available. Chuang said it is expected that between seven and 10 atoms
will be used in tandem in more advanced quantum computers within the
next two years.