Anisotropic memory effects in confined colloidal diffusion
Anisotropic memory effects in confined colloidal diffusion
复制标题
DOI：
10.1103/physrevlett.100.240604
复制
发表时间：
2008-06-20
影响因子：
8.6
通讯作者：
Forro, Laszlo
中科院分区：
文献类型：
--
作者：
Jeney, Sylvia;Lukic, Branimir;Forro, Laszlo
在流体动力学记忆是显着的时候，一个光学捕获的球附近的壁的运动进行了研究。首先，我们量化，在散装，所产生的限制的影响，从捕获的潜力对球的速度自相关函数C（t）。接下来，我们研究了当球体接近曲面时，C（t）分裂为C（平行于）（t）和C（垂直于）（t）。因此，由于流体动力学回流和壁效应之间的微妙相互作用，我们监测了从远离壁的缓慢t（-3/2）长时间尾部到更快的t（-5/2）衰减的交叉。最后，我们讨论了由此产生的非对称的时间依赖的扩散系数。
The motion of an optically trapped sphere constrained by the vicinity of a wall is investigated at times where hydrodynamic memory is significant. First, we quantify, in bulk, the influence of confinement arising from the trapping potential on the sphere's velocity autocorrelation function C(t). Next, we study the splitting of C(t) into C(parallel to)(t) and C(perpendicular to)(t), when the sphere is approached towards a surface. Thereby, we monitor the crossover from a slow t(-3/2) long-time tail, away from the wall, to a faster t(-5/2) decay, due to the subtle interplay between hydrodynamic backflow and wall effects. Finally, we discuss the resulting asymmetric time-dependent diffusion coefficients.