中国物理B ›› 2013, Vol. 22 ›› Issue (6): 60513-060513.doi: 10.1088/1674-1056/22/6/060513

• GENERAL • 上一篇    下一篇

Brownian localization: A generalized coupling model yielding a nonergodic Langevin equation description

刘剑, 王海燕, 包景东   

  1. Department of Physics, Beijing Normal University, Beijing 100875, China
  • 收稿日期:2012-12-01 修回日期:2013-02-20 出版日期:2013-05-01 发布日期:2013-05-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11175021).

Brownian localization: A generalized coupling model yielding a nonergodic Langevin equation description

Lin Jian (刘剑), Wang Hai-Yan (王海燕), Bao Jing-Dong (包景东)   

  1. Department of Physics, Beijing Normal University, Beijing 100875, China
  • Received:2012-12-01 Revised:2013-02-20 Online:2013-05-01 Published:2013-05-01
  • Contact: Bao Jing-Dong E-mail:jdbao@bnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11175021).

摘要: A minimal system-plus-reservoir model yielding a nonergodic Langevin equation is proposed, which origins from cubic-spectral density of environmental oscillators and momentum-dependent coupling. This model allows the ballistic diffusion and classical localization simultaneously, in which the fluctuation-dissipation relation is still satisfied but the Khinchin theorem is broken. The asymptotical equilibrium for nonergodic system requires the initial thermal equilibrium, however, when the system starts from nonthermal conditions, it does not approach the equilibration even a nonlinear potential is used to bound particle, this can be confirmed by the zeroth law of thermodynamics. In the dynamics of Brownian localization, due to the memory damping function inducing a constant term, our results show that the stationary distribution of the system depends on its initial preparation of coordinate rather than momentum. The coupled oscillator chain with a fixed end boundary acts as such heat bath, which has long been used in studies of collinear atom/solid-surface scattering and lattice vibration, we investigate this problem from the viewpoint of nonergodicity.

关键词: ocalization, nonergodicity, generalized coupling model, coupled oscillator chain

Abstract: A minimal system-plus-reservoir model yielding a nonergodic Langevin equation is proposed, which origins from cubic-spectral density of environmental oscillators and momentum-dependent coupling. This model allows the ballistic diffusion and classical localization simultaneously, in which the fluctuation-dissipation relation is still satisfied but the Khinchin theorem is broken. The asymptotical equilibrium for nonergodic system requires the initial thermal equilibrium, however, when the system starts from nonthermal conditions, it does not approach the equilibration even a nonlinear potential is used to bound particle, this can be confirmed by the zeroth law of thermodynamics. In the dynamics of Brownian localization, due to the memory damping function inducing a constant term, our results show that the stationary distribution of the system depends on its initial preparation of coordinate rather than momentum. The coupled oscillator chain with a fixed end boundary acts as such heat bath, which has long been used in studies of collinear atom/solid-surface scattering and lattice vibration, we investigate this problem from the viewpoint of nonergodicity.

Key words: ocalization, nonergodicity, generalized coupling model, coupled oscillator chain

中图分类号:  (Nonequilibrium and irreversible thermodynamics)

  • 05.70.Ln
05.40.Jc (Brownian motion) 05.40.Ca (Noise)