Anomalous barrier escape: The roles of noise distribution and correlation

作者：Hu, Meng; Zhang, Jia-Ming; Bao, Jing-Dong^*

来源：Journal of Chemical Physics, 2017, 146(20): 204103.

DOI：10.1063/1.4983651

• LEVY FLIGHTS
• CORRELATION CASCADES
• ORNSTEIN-UHLENBECK
• DYNAMICAL-SYSTEMS
• KRAMERS PROBLEM
• REACTIVE FLUX
• DIFFUSION
• SPACE
• DRIVEN
• MODELS

We study numerically and analytically the barrier escape dynamics of a particle driven by an underlying correlated Levy noise for a smooth metastable potential. A "quasi-monochrome-color" Levy noise, i.e., the first-order derivative variable of a linear second-order differential equation subjected to a symmetric alpha-stable white Levy noise, also called the harmonic velocity Levy noise, is proposed. Note that the time-integral of the noise Green function of this kind is equal to zero. This leads to the existence of underlying negative time correlation and implies that a step in one direction is likely followed by a step in the other direction. By using the noise of this kind as a driving source, we discuss the competition between long flights and underlying negative correlations in the metastable dynamics. The quite rich behaviors in the parameter space including an optimum alpha for the stationary escape rate have been found. Remarkably, slow diffusion does not decrease the stationary rate while a negative correlation increases net escape. An approximate expression for the Levy-Kramers rate is obtained to support the numerically observed dependencies. Published by AIP Publishing.

• 出版日期2017-5-28
• 单位北京师范大学