中国物理B ›› 2004, Vol. 13 ›› Issue (5): 778-782.doi: 10.1088/1009-1963/13/5/035

• 8000 CROSSDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Depinning dynamics of driven colloids with random pinning: a numerical study

陈江星, 冯春木, 汪友梅, 曹义刚, 焦正宽   

  1. Department of Physics, Zhejiang University, Hangzhou 310027, China
  • 收稿日期:2003-10-17 修回日期:2003-12-01 出版日期:2005-07-06 发布日期:2005-07-06
  • 基金资助:
    Project supported by the Ministry of Science and Technology of China (Grant No NKBRSF-G19990646), the Postdoctoral Science Foundation of China, and the Scientific Research Foundation of State Education Ministry for Returned Overseas Chinese Scholars.

Depinning dynamics of driven colloids with random pinning: a numerical study

Chen Jiang-Xing (陈江星), Feng Chun-Mu (冯春木), Wang You-Mei (汪友梅), Cao Yi-Gang (曹义刚), Jiao Zheng-Kuan (焦正宽)   

  1. Department of Physics, Zhejiang University, Hangzhou 310027, China
  • Received:2003-10-17 Revised:2003-12-01 Online:2005-07-06 Published:2005-07-06
  • Supported by:
    Project supported by the Ministry of Science and Technology of China (Grant No NKBRSF-G19990646), the Postdoctoral Science Foundation of China, and the Scientific Research Foundation of State Education Ministry for Returned Overseas Chinese Scholars.

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摘要： Using Langevin simulations, we have investigated numerically the depinning dynamics of driven two-dimensional colloids subject to the randomly distributed point-like pinning centres. With increasing strength of pinning, we find a crossover from elastic to plastic depinnings, accompanied by an order to disorder transition of state and a substantial increase in the depinning force. In the elastic regime, no peaks are found in the differential curves of the velocity－force dependence (VFD) and the transverse motion is almost none. In addition, the scaling relationship between velocity and force is found to be valid above depinning. However, when one enters the plastic regime, a peak appears in the differential curves of VFD and transverse diffusion occurs above depinning. Furthermore, history dependence is found in the plastic regime.

Abstract: Using Langevin simulations, we have investigated numerically the depinning dynamics of driven two-dimensional colloids subject to the randomly distributed point-like pinning centres. With increasing strength of pinning, we find a crossover from elastic to plastic depinnings, accompanied by an order to disorder transition of state and a substantial increase in the depinning force. In the elastic regime, no peaks are found in the differential curves of the velocity－force dependence (VFD) and the transverse motion is almost none. In addition, the scaling relationship between velocity and force is found to be valid above depinning. However, when one enters the plastic regime, a peak appears in the differential curves of VFD and transverse diffusion occurs above depinning. Furthermore, history dependence is found in the plastic regime.

Key words: colloid, depinning, crossover

中图分类号:  (Colloids)

  • 82.70.Dd
02.60.-x (Numerical approximation and analysis) 66.30.Dn (Theory of diffusion and ionic conduction in solids) 64.60.-i (General studies of phase transitions)