Collective effects and possible high temperature viscosity quantization in high temperature metallic liquids: theory and experiment

We introduce notions concerning locally preferred structures and discuss
recent experimental and numerical results on metallic fluids that suggest
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 standard 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 dynamics.