Harmonic Chain with Velocity Flips: Thermalization and Kinetic Theory

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• 作者：Jani Lukkarinen ; Matteo Marcozzi ; Alessia Nota
• 关键词：Velocity flip model ; Kinetic theory ; Boltzmann equations ; Lattice dynamics ; Diffusion processes
• 刊名：Journal of Statistical Physics
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：165
• 期：5
• 页码：809-844
• 全文大小：712 KB
• 刊物类别：Physics and Astronomy
• 刊物主题：Physics
  Statistical Physics
  Mathematical and Computational Physics
  Physical Chemistry
  Quantum Physics
  
• 出版者：Springer Netherlands
• ISSN：1572-9613
• 卷排序：165

文摘

We consider the detailed structure of correlations in harmonic chains with pinning and a bulk velocity flip noise during the heat relaxation phase which occurs on diffusive time scales, for \(t=O(L^2)\) where L is the chain length. It has been shown earlier that for non-degenerate harmonic interactions these systems thermalize, and the dominant part of the correlations is given by local thermal equilibrium determined by a temperature profile which satisfies a linear heat equation. Here we are concerned with two new aspects about the thermalization process: the first order corrections in 1 / L to the local equilibrium correlations and the applicability of kinetic theory to study the relaxation process. Employing previously derived explicit uniform estimates for the temperature profile, we first derive an explicit form for the first order corrections to the particle position-momentum correlations. By suitably revising the definition of the Wigner transform and the kinetic scaling limit we derive a phonon Boltzmann equation whose predictions agree with the explicit computation. Comparing the two results, the corrections can be understood as arising from two different sources: a current-related term and a correction to the position-position correlations related to spatial changes in the phonon eigenbasis.