Non-Markovian diffusion of the stochastic system with a biexponentical dissipative memory kernel

作者：Xie Wen-Xian^*; Xu Peng-Fei; Cai Li; Li Dong-Ping

来源：Acta Physica Sinica, 2013, 62(8): 080503.

DOI：10.7498/aps.62.080503

• thermal noise
• non-Markovian diffusion
• generalized Langevin equation
• correlation

In this paper, second-moments of the responses are analytically solved by the Laplace transform in a coupling two-degree-of-freedom system with a biexponentical dissipative memory kernel function driven by a thermal broadband noise. The mean square displacement < x(2)(t)> is different from anomalous diffusion (i.e. < x(2)(t)> proportional to t(alpha) (0 < alpha < 2, alpha not equal 1)), which is induced by the single-degree-of-freedom generalized Langevin equation. The oscillation-diffusion of < x(2)(t)> with the change of time and noise parameters is observed generally. According to our analysis, a particle confined by the harmonic potential can escape with the help of the coupling-damping factor B. The diffusion of < x(2)(t)> aggravates with B increasing. However, < x(2)(t)> tends to the stationary state with the increase of the friction coefficient. Further, if the two thermal noises are in cross-correlation, smaller cross-correlation time has a deeper influence on second-moments. Meanwhile, the diffusion aggravates and the cross-correlation between two displacements strengthens markedly with cross-correlation strength increasing. It is consistent with physical intuition.

• 出版日期2013-4
• 单位西北工业大学