Lecturer: Prof. Zohar Nussinov
Affiliation: Department of Physics,
Washington University
Abstract:
We introduce notions concerning locally
preferred structures and discuss recent
experimental and numerical results on
metallic fluids that indicate the onset of
cooperative dynamics as a liquid is
supercooled to form a glass. We will further
suggest that certain quantum effects may
emerge in the high temperature limit of
general "classical fluids". Towards this end,
we will invoke the WKB approximation,
extend the usual kinetic theory by taking
into account a possible minimal quantum
time scale, apply ideas from transition state
theory, and relate (via Planck's constant) the
thermodynamic entropy to periods of semi-
classical trajectories. Taken together, these
will suggest that, on average, the
extrapolated high temperature viscosity of
general liquids may tend to a value set by
the product of the particle number density n
and Planck's constant h. Experimental
measurements of an ensemble of 23
metallic fluids indicate that might indeed be
the case; the extrapolated high temperature
viscosity of each of these liquids divided
(for each respective fluid) by its value of nh
veers towards a Gaussian with an ensemble
average value that is close to unity up to an
error of size 0.6%. We invoke similar ideas
to discuss other transport properties to
suggest how simple behaviors may appear
including resistivity saturation and linear T
resistivity may appear naturally. This
approach suggests that minimal time lags
may be present in general fluid dynamic.