欠阻尼动力学系统跨越涨落势垒的扩散
2020-11-29
文章来源: 未知
  ■ Diffusion over a fluctuating barrier in underdamped dynamics
  
  欠阻尼动力学系统跨越涨落势垒的扩散
  
  作者:毛俊雯,沈彩万
  
  
  摘要:本文从一个由加性噪声和乘性噪声驱动的朗之万方程出发,研究了欠阻尼动力学系统涨落势垒作用下的扩散性质。势垒的涨落由指数关联的高斯色噪声描述。本文给出了相关的一阶矩和二阶矩的解析解。更进一步地,通过直接模拟的方法计算得到了布朗粒子越过涨落势垒的渐进概率。结果表明涨落的关联性在跨越势垒动力学问题中起着重要作用。
  
  Abstract: We apply a Langevin model by imposing additive and multiplicative noises to study thermally activated diffusion over a fluctuating barrier in underdamped dynamics. The barrier fluctuation is characterized by Gaussian colored noise with exponential correlation. We present the exact solutions for the first and second moments. Furthermore, we use direct simulations to calculate the asymptotic probability for a Brownian particle passing over the fluctuating barrier. The results indicate that the correlation of the fluctuating barrier is crucial for barrier crossing dynamics.