Ai Bao-Quan
Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China.
Phys Rev E. 2017 Jul;96(1-1):012131. doi: 10.1103/PhysRevE.96.012131. Epub 2017 Jul 14.
Diffusion and rectification of Brownian particles powered by a rotating wheel are numerically investigated in a two-dimensional channel. The nonequilibrium driving comes from the rotating wheel, which can break thermodynamical equilibrium and induce the directed transport in an asymmetric potential. It is found that the direction of the transport along the potential is determined by the asymmetry of the potential and the position of the wheel. The average velocity is a peaked function of the angular speed (or the diffusion coefficient) and the position of the peak shifts to large angular speed (or diffusion coefficient) when the diffusion coefficient (or the angular speed) increases. There exists an optimal angular speed (or diffusion coefficient) at which the effective diffusion coefficient takes its maximal value. Remarkably, the giant acceleration of diffusion is observed by suitably adjusting the system parameters. The parameters corresponding to the maximum effective diffusion coefficient are not the same as the parameters at which average velocity is maximum.
在二维通道中对由旋转轮驱动的布朗粒子的扩散和整流进行了数值研究。非平衡驱动来自旋转轮，它可以打破热力学平衡并在非对称势场中诱导定向输运。研究发现，沿势场的输运方向由势场的不对称性和轮子的位置决定。平均速度是角速度（或扩散系数）的峰值函数，当扩散系数（或角速度）增加时，峰值位置向较大的角速度（或扩散系数）移动。存在一个最佳角速度（或扩散系数），此时有效扩散系数取最大值。值得注意的是，通过适当调整系统参数可观察到扩散的巨大加速。对应于最大有效扩散系数的参数与平均速度最大时的参数不同。
