Download Quantum molecular dynamics simulations for warm dense matter

Quantum molecular dynamics simulations for warm dense matter
R. Redmer, M. French, B. Holst, A. Kietzmann, N. Nettelmann
(Rostock, Germany)
Abstract
The term warm dense matter characterizes states of matter between
cold condensed matter (solids, liquids) and hot plasmas which are relevant
for, e.g., planetary interiors and inertial connement fusion experiments.
The physical properties of warm dense matter are characterized by strong
correlations. Therefore, studies of the equation of state (EOS) and ionization degree, of transport properties such as the electrical conductivity, of
structural properties such as the pair correlation function and the dynamic
structure factor are sensitive with respect to many-particle eects and
allow tests of theoretical models for the strongly coupled region. Quantum molecular dynamics (QMD) simulations allow to determine such a
broad spectrum of properties of strongly correlated systems within a strict
physical picture. They combine density functional theory (DFT) for the
electron system and classical molecular dynamics simulations for the ions.
DFT methods become increasingly accurate and predicitve, and the numerical tools for sophisticated quantum calculations for even larger systems are generally available today. Therefore, QMD simulations represent
a valuable if not unique tool to treat strongly correlated and disordered
systems as, e.g., warm dense matter.
The lecture gives a broad overview of the experimental methods for
warm dense matter studies. We then introduce the QMD method and give
insight in some technical and numerical details. We apply the method to
warm dense matter states and show some results for, e.g.,
structural and thermodynamic properties of expanded liquid alkali
metals for which accurate EOS and conductivity data are available
so that the QMD method can be tested,
thermodynamic and transport properties of shock-compressed hydrogen and helium as the most abundant elements in nature which
are of high relevance for astrophysics,
consequences for planetary physics, especially for models of the interior of giant planets such as Jupiter and Saturn or of extrasolar
planets,
the interplay between thermodynamic phase transitions and the nonmetalto-metal transition in these systems,
the dynamic structure factor for warm dense matter which can be determined by X-ray Thomson scattering experiments that are planned,
e.g., at the FLASH facility at DESY Hamburg.
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