Thermalization of oscillator chains with onsite anharmonicity and comparison with kinetic theory.
Abstract
We perform microscopic molecular dynamics simulations of particle chains with an onsite
anharmonicity to study relaxation of spatially homogeneous states to equilibrium,
and directly compare the simulations with the corresponding Boltzmann-Peierls kinetic
theory. The Wigner function serves as a common interface between the microscopic and
kinetic level. We demonstrate quantitative agreement after an initial transient time
interval. In particular, besides energy conservation, we observe the additional quasiconservation
of the phonon density, defined via an ensemble average of the related microscopic
field variables and exactly conserved by the kinetic equations. On superkinetic time
scales, density quasiconservation is lost while energy remains conserved, and we find
evidence for eventual relaxation of the density to its canonical ensemble value. However,
the precise mechanism remains unknown and is not captured by the Boltzmann-Peierls
equations.
Type
Journal articlePermalink
https://hdl.handle.net/10161/14113Published Version (Please cite this version)
10.1103/PhysRevE.94.062104Publication Info
Mendl, Christian B; Lu, Jianfeng; & Lukkarinen, Jani (2016). Thermalization of oscillator chains with onsite anharmonicity and comparison with
kinetic theory. Phys Rev E, 94(6-1). pp. 062104. 10.1103/PhysRevE.94.062104. Retrieved from https://hdl.handle.net/10161/14113.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Jianfeng Lu
Professor of Mathematics
Jianfeng Lu is an applied mathematician interested in mathematical analysis and algorithm
development for problems from computational physics, theoretical chemistry, materials
science and other related fields.More specifically, his current research focuses include:Electronic
structure and many body problems; quantum molecular dynamics; multiscale modeling
and analysis; rare events and sampling techniques.

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