阻尼系数和质量对粒子定向输运相干性的影响  

Effects of the friction coefficlient and mass on the transport coherence of Brownian particles

作　　者：杨明[1] 姚勇[1] 曹力[2] 吴大进[2] 

机构地区：[1]华中科技大学物理系,湖北武汉430074 [2]华中科技大学激光技术国家重点实验室,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2007年第2期116-118,共3页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(10275025)

摘　　要：运用二阶龙格-库塔方法,对一维倾斜周期势中的欠阻尼运动进行了计算机模拟.结果发现:粒子定向输运的平均速度和扩散系数都随着阻尼系数增大而减少,并且扩散系数减小得更快,这直接导致了平均速度和扩散系数的比值,也就是Péclet值随之增大,从而使系统获得了更高的相干性.同时发现,当阻尼系数不变时,Péclet值随着粒子质量增大而减小.The underdamped motion of the Brownian particle in a tilted periodic potential was mulated by Runge-Kutta algorithms. The results show that both the average velocity and effective diffusion coefficient of the particle decrease as the friction coefficient increases, but the latter decreases more rapidly. Therefore, the ratio of the average velocity to the effective diffusion coefficient （i. e. Péclet number） increases with the friction coefficient, which means that the transport becomes more coherent when the friction coefficient increases. It is also shown that when the friction coefficient keeps constant, the Péclet number decreases with the particle mass.

关 键 词：相干输运 高斯白噪声 倾斜周期势 Péclet值 扩散系数 平均速度 

分 类 号：O415.2[理学—理论物理]