[Paleopsych] The impact of its environment on a quantum computer
shovland at mindspring.com
Fri Apr 15 13:29:53 UTC 2005
Scientists have discovered how the performance of a quantum computer can be
affected by its surrounding environment. The study, published in the latest
issue of the journal Science, will help engineers to better understand how
to integrate quantum components into a standard office computer - moving us
one step closer to a future of quantum computing.
The collaborative team from the London Centre for Nanotechnology,
University College London (UCL), the Paul Scherrer Institute/ETH in
Switzerland and the Universities of Chicago and Copenhagen, have shown how
its environment can radically alter the behaviour of a quantum computer, an
effect which is not present for conventional computers of the type that
exist now on our desktops.
Professor Gabriel Aeppli of UCL's Dept of Physics and the Director of the
London Centre for Nanotechnology says: "One of the most important questions
in natural sciences is whether quantum mechanics is relevant to everyday
experience. The famous puzzle of whether Schroedinger's cat is dead or
alive is the most graphic representation of this question, traditionally
considered an academic point of no real practical import.
"However, the recent demand for secure communications and ultra-high speed
computation has made the answer highly relevant to future technology where
quantum 'qubits' replace the classical binary bits 0 and 1 on which current
digital electronics and communications rely.
"To engineer quantum computers it is necessary for the qubits to be stable
in realistic settings, such as the integrated circuit packages in a typical
office computer. Physicists refer to such settings as the 'environment', or
more picturesquely, the 'bath', and the challenge is to control and
minimize the interactions of the qubits with the bath.
"Quantum engineering will require careful attention to the 'baths' in which
the new devices will be immersed, in the same way that we worry about
turbulent air conditions when we design aircraft." Baths by their very
nature can be difficult to define and therefore the systematic study of
interactions between qubits and baths is in its infancy. The new work shows
how a well-specified bath affects the qubits in a crystal which behaves as
a very primitive quantum computer. For example, the bath will change how
the qubits will move in response to stimuli such as radio waves. The work
also suggests that the effect can be controlled by radio waves themselves
and by the temperature of the bath.
More information about the paleopsych