Multiple current reversals and diffusion enhancement in a symmetrical periodic potential.
Multiple current reversals and diffusion enhancement in a symmetrical periodic potential.
复制标题
DOI：
10.1063/1.4745853
复制
发表时间：
2012-08
期刊：
影响因子：
2.9
通讯作者：
C. Zeng;Hua Wang;L. Nie
中科院分区：
文献类型：
--
作者：
C. Zeng;Hua Wang;L. Nie
研究了过阻尼和欠阻尼情况下对称周期性势中布朗粒子的传输和扩散，其中棘轮势由外部无偏时间周期力以及热和势波动之间的相关性驱动。结果表明，两个噪声之间的相关性打破了布朗粒子在特定方向上产生运动的势的对称性，并且电流可以通过改变噪声相关性的符号来反转其方向。对于过阻尼情况，系统参数仅感应定向电流，噪声相关性抑制过阻尼布朗粒子的扩散。然而，对于欠阻尼情况，随着系统参数的增加，电流会多次反转其方向，即观察到多次电流反转，并且噪声负相关抑制了欠阻尼布朗粒子的扩散，而噪声正相关则增强了欠阻尼布朗粒子的扩散。
Transport and diffusion of Brownian particles in a symmetrical periodic potential were investigated for both overdamped and underdamped cases, where the ratchet potential is driven by an external unbiased time periodic force and correlation between thermal and potential fluctuations. It is shown that the correlation between two noises breaks the symmetry of the potential to generate motion of the Brownian particles in particular direction, and the current can reverse its direction by changing the sign of the noise correlation. For the overdamped case, the systemic parameters only induce the directed current, and the noise correlation suppresses the diffusion of the overdamped Brownian particles. However for the underdamped case, the current reverses its direction multiple times with increasing the systemic parameters, i.e., the multiple current reversal is observed, and the noise negative correlation suppresses the diffusion of the underdamped Brownian particles, while the noise positive correlation enhances it.