On the determination
and ramifications of chaos
in many-body systems
Oak Ridge National Laboratory
This is an abstract
for a poster to be presented at the
Fifth
Foresight Conference on Molecular Nanotechnology.
There will be a link from here to the full article when it is
available on the web.
The nature and role of chaotic dynamics in molecular systems
has been studies for a number of years for systems composed of
few particles. The extension of this knowledge to larger systems
has not been perused in detail. While it is known that the
breakdown of the normal coordinate analysis as well as the
increasing importance of the coupling of different degrees of
freedom corresponds to the transition of the classical phase
space from regular to chaotic behavior, this transition and its
quantum implications have only been studied in detail for atomic
and simple molecular systems with few degrees of freedom
(typically 2 or 3). Up to now there have been no systematic
studies of the transition from regular to chaotic dynamics in
systems with many degrees of freedom.
We have used a number of techniques for quantifying a system
dynamics for a given set of parameters and also to discover how
the dynamics of a system changes with some parameter
(temperature). The dynamics of macromolecules as a function of
temperature were quantified and shown to have transitions from
low dimensional chaos to high (or higher) dimensional dynamics at
certain temperatures. The results presented in this poster
provide qualitative and quantitative analysis of the structure
and the dynamics of a macromolecule in the region where normal
coordinate analysis is no longer applicable and advance a better
understanding of classical chaotic dynamics in many
degree-of-freedom systems. Results indicate that the
dimensionality of chaotic dynamics for a model of a polyethylene
chain as a function of temperature can only be characterized for
a very narrow range of extremely low temperatures (0 - 2K),
suggesting highly chaotic dynamics as low as 10 K.
Research sponsored by the Division of Materials Sciences,
Office of Basic Energy Sciences, U.S. Department of Energy under
contract DE-AC05-96OR22464 with Lockheed-Martin Energy Research
Corp.
*Corresponding Address:
David E. Newman, Oak Ridge National Laboratory, Fusion Energy
Division, P. O. Box 2008, Oak Ridge, TN 37831-6197, ph:
423-576-0381, fax: 423-576-5235, email: [email protected]
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