A Quantum Computer... A Future Technology


Quantum Computer... A Future Technology

By the strange laws of quantum mechanics,

Folger, a senior editor at Discover, notes, an electron, proton, or other
subatomic particle is "in more than one place at a time," because individual
particles behave like waves, these different places are different states
that an atom can exist in simultaneously. Ten years ago, Folger writes,

David Deutsch, a physicist at Oxford University, argued that it may be
possible to build an extremely
powerful computer based on this peculiar
reality. In 1994, Peter Shor, a mathematician at AT&T Bell Laboratories
in New Jersey, proved that, in theory at least, a full-blown quantum computer
could factor even the largest numbers in seconds--an accomplishment impossible
for even the fastest conventional computer.

An outbreak of theories and
discussions of the possiblity of buildig a quantum computer now permeates
itself thoughtout the quantum fields of technology and research.

It\'s roots can be traced back to 1981, when Richard Feynman noted that
physicists always seem to run into computational problems when they try
to simulate a system in which quantum mechanics would take place.

The caluclations involving the behavior of atoms, electrons, or photons,
require an immense amount of time on today\'s computers. In 1985 in

Oxford England the first description of how a quantum computer might work
surfaced with David Deutsch\'s theories. The new device would not
only be able to surpass today\'s computers in speed, but also could perform
some logical operations that conventional ones couldn\'t.

This reasearch began looking into
actually constructing a device and with the go ahead and additional funding
of AT&T Bell Laboratories in Murray Hill, New Jersey a new member of
the team was added. Peter Shor made the discovery that quantum computation
can greatly speed factoring of whole numbers. It\'s more than just
a step in micro-computing technology, it could offer insights into real
world applications such as cryptography. "There is a hope at the
end of the tunnel that quantum computers may one day become a reality,"
says Gilles Brassard of University of Montreal.

Quantum Mechanics give an unexpected
clarity in the description of the behavior of atoms, electrons, and photons
on the microscopic levels. Although this information isn\'t applicable
in everday household uses it does certainly apply to every interaction
of matter that we can see, the real benefits of this knowledge are just
beginning to show themselves. In our computers, circut boards are
designed so that a 1 or a 0 is represented by differering amounts of electriciy,
the outcome of one possiblity has no effect on the other. However,
a problem arises when quantum theories are introduced, the outcomes come
from a single piece of hardware existing in two seperate realities and
these realites overlap one another affecting both outcomes at once.

These problems can become one of the greatest strengths
of the new computer however, if it is
possible to program the outcomes in such a way so that undesirable effects
cancel themselves out while the positive ones reinforce each other.

This quantum system must be able to program the equation into it, verify
it\'s computation, and extract the results.

Several possible systems have been
looked at by researchers, one of which involves using electrons, atoms,
or ions trapped inside of magnetic fields, intersecting lasers would then
be used to excite the confined particles to the right wavelength and a
second time to restore the particles to their ground state. A sequence
of pulses could be used to array the particles into a pattern usuable in
our system of equations. Another possibility by Seth Lloyd of MIT
proposed using organic-metallic polymers (one dimensional molecules made
of repeating atoms). The energy states of a given atom would be determined
by it\'s interation with neighboring atoms in the chain. Laser pulses
could be used to send signals down the polymer chain and the two ends would
create two unique energy states. A third
proposal was to replace the organic molecules
with crystals in which information would be stored in the crystals in specific
frequencies that could be processed with addtional pulses.

The atomic nuclei, spining in either
of two states (clockwise or counterclockwise) could be programmed with
a tip of a atomic microscope, either "reading" it\'s surface or altering
it, which of course would be "writing" part of information storage.

"Repetitive motions of the tip, you could eventually write out any desired
logic circut, " DiVincenzo said. This power comes at a price however,
in that these states would have to remain completely isolated from everything,
including a stray photon. These outside influences would accumulate,
causing the system to wander off