Sliding Charge-Density Waves
Finite--Size Fluctuations in Sliding Charge--Density Waves: Rob
Thorne's Skepticism Is Vindicated. (Myers;
63, 64)
Chris Myers wanted a thesis project involving dynamical systems, so I
suggested thinking about the dynamics of charge--density waves. We
gradually got sucked into using the methods of critical phenomena and
scaling, despite Rob Thorne's assertion that the experiments purportedly
seeing scaling were wrong. He said that every sample he looked at
looked completely different, and that the experiments published were
those that looked only at one sample. Myers did a marvelous job of
finding new algorithms for locating the transition, finding new
implementations that accelerating the dynamics, developing graphical
displays and command--line interfaces for exploring the parameter space,
finding scaling methods and extracting exponents.
A picture of the sliding of a CDW by one wavelength, right at
depinning. The first point to move is marked in blue: the last is red.
The animation (using DynamicLattice) is one of the demos available for
LASSPTOOLS.
In the end, we found
a new finite--size scaling region, in which every sample looks completely
different. Matching our system size to Thorne and Brock's new
measurements of the correlation length, our simulations now looked strikingly
similar to data taken straight from Thorne's thesis.
Links Back
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Sethna's Research 90-94
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Entertaining Science done at
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LASSP.
Last modified: February 8, 1995
James P. Sethna, sethna@lassp.cornell.edu
Statistical Mechanics: Entropy, Order Parameters, and Complexity,
now available at
Oxford University Press
(USA,
Europe).
