受驱胶体的脱钉特性研究

Study on Depinning Dynamics of Driven Colloids

利用Langevin方程数值模拟钉扎中心随机分布的受驱二维胶体的脱钉特性,发现胶体的相互作用强度对胶体脱钉有重要影响。随着胶体相互作用强度的降低,胶体的脱钉存在从弹性到塑性的渡越。临界钉扎力在渡越区陡然增加。当胶体进入塑性流动区,速度-驱动力曲线上开始出现台阶,并伴随速度-驱动力曲线的交叠。

Using Langevin dynamics,we numerically study the depinning dynamics of driven two-dimensional colloids with randomly distributed point-like centers.We find that the strength of colloidal interaction has an important influence on the depinning dynamics.An increase in the strength of colloidal interaction leads to a crossover from elastic to plastic depinnings.The critical pinning force has a sudden increase in the crossover.More than that,we find for the first time that steps occur in the curves of velocity-driven force dependence when plastic flows take place,accompanying a cross between different curves of velocity-driven force dependence.