Direct observation of nondiffusive motion of a Brownian particle -: art. no. 160601
Direct observation of nondiffusive motion of a Brownian particle -: art. no. 160601
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DOI：
10.1103/physrevlett.95.160601
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发表时间：
2005-10-14
影响因子：
8.6
通讯作者：
Florin, EL
中科院分区：
文献类型：
--
作者：
Lukic, B;Jeney, S;Florin, EL
利用光阱干涉技术，以纳米级的空间分辨率和微秒级的时间分辨率记录了浸没在流体中的单个微米级球体的热位置涨落。我们发现，在雅阁运动理论，包括流体动力学记忆效应，从弹道扩散运动的过渡被延迟到显着更长的时间比预测的标准朗之万方程。这种延迟是流体惯性的结果。在所研究的最短时间尺度上，球体的惯性有一个很小但可测量的影响。
The thermal position fluctuations of a single micron-sized sphere immersed in a fluid were recorded by optical trapping interferometry with nanometer spatial and microsecond temporal resolution. We find, in accord with the theory of Brownian motion including hydrodynamic memory effects, that the transition from ballistic to diffusive motion is delayed to significantly longer times than predicted by the standard Langevin equation. This delay is a consequence of the inertia of the fluid. On the shortest time scales investigated, the sphere's inertia has a small, but measurable, effect.