外力作用下反馈耦合布朗棘轮的定向输运

本文研究了处于外力作用下双阱棘轮势中两个反馈耦合布朗粒子的定向输运性能. 通过对过阻尼朗之万方程的数值求解, 详细讨论了外力、热噪声与势阱的不对称参数等对耦合布朗粒子的平均速度、 有效扩散系数及Pe数的影响. 研究发现, 平均速度随外力呈周期性的变化规律. 同时耦合系统存在最优噪声强度会使定向输运达到最强. 值得指出的是棘轮系统可通过改变双阱势的结构来获得较强的定向流. 关键词： 耦合布朗棘轮 外力 双阱棘轮势 平均速度

Influnce of the external force on the directed transport of feedback-coupled Brownian ratchet

The directed transport performance of two coupled Brownian particles in the double-well ratchet potential under the external force has been studied in this paper. Langevin equation in the overdamped regime is solved numerically. The influence of the external force, the thermal noise, and the asymmetric parameter of the potential on the transport properties of the coupled Brownian particles including the average velocity, the effective diffusion coefficient D_eff , and the Pe number, is discussed in detail. It is found that the average velocity changes periodically under the external force. Meanwhile, there is an optimal value of the intensity of the thermal noise at which the current reaches the maximum. It is worthwhile to point out that the enhancement of the current can be achieved by changing the structure of the ratchet potential.