Thermalization of oscillator chains with onsite anharmonicity and comparison with kinetic theory.

Journal Article

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.

Full Text

Duke Authors

Cited Authors

  • Mendl, CB; Lu, J; Lukkarinen, J

Published Date

  • December 2, 2016

Published In

Volume / Issue

  • 94 / 6-1

Start / End Page

  • 062104 -

PubMed ID

  • 28085301

Electronic International Standard Serial Number (EISSN)

  • 2470-0053

International Standard Serial Number (ISSN)

  • 2470-0045

Digital Object Identifier (DOI)

  • 10.1103/physreve.94.062104

Language

  • eng