Non-Gaussian statistics for the motion of self-propelled Janus particles: experiment versus theory.
Non-Gaussian statistics for the motion of self-propelled Janus particles: experiment versus theory.
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DOI：
10.1103/physreve.88.032304
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发表时间：
2013-08
期刊：
影响因子：
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通讯作者：
Xu Zheng;B. ten Hagen;A. Kaiser;Meiling Wu;Hai-hang Cui;Z. Silber-Li;H. Löwen
中科院分区：
文献类型：
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作者：
Xu Zheng;B. ten Hagen;A. Kaiser;Meiling Wu;Hai-hang Cui;Z. Silber-Li;H. Löwen
球形Janus粒子是活跃布朗物体的最突出的例子之一。本文从实验和理论两方面研究了这种微泳者的扩散泳运动。发现了三个阶段：简单的布朗运动在短时间内，超扩散在中间时间，并最终扩散行为再次在长时间内。在实验中观察到的这三个制度进行了比较与理论模型的自推进粒子的平移和旋转运动耦合的朗之万动力学。除了均方位移，还讨论了更高的位移矩。特别是，关于自推进粒子的非高斯行为的理论预测在实验中得到验证。此外，完整的位移概率分布进行了分析，在协议与布朗动力学模拟无论是一个非常宽的峰值或一个明显的双峰结构被发现，根据实验条件。
Spherical Janus particles are one of the most prominent examples for active Brownian objects. Here, we study the diffusiophoretic motion of such microswimmers in experiment and in theory. Three stages are found: simple Brownian motion at short times, superdiffusion at intermediate times, and finally diffusive behavior again at long times. These three regimes observed in the experiments are compared with a theoretical model for the Langevin dynamics of self-propelled particles with coupled translational and rotational motion. Besides the mean square displacement also higher displacement moments are addressed. In particular, theoretical predictions regarding the non-Gaussian behavior of self-propelled particles are verified in the experiments. Furthermore, the full displacement probability distribution is analyzed, where in agreement with Brownian dynamics simulations either an extremely broadened peak or a pronounced double-peak structure is found, depending on the experimental conditions.