Isele Marc, Hofmann Kay, Erbe Artur, Leiderer Paul, Nielaba Peter
Physics Department, University of Konstanz, 78457 Konstanz, Germany.
Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany.
Phys Rev E. 2023 Sep;108(3-1):034607. doi: 10.1103/PhysRevE.108.034607.
We investigate the lane formation in nonequilibrium systems of colloidal particles moving in parallel that are driven by the force of gravity. For this setup, an experimental implementation of a channel on a slope can be conceptualized. We employ the Brownian dynamics algorithm and confine the repulsive particles with hard walls based on the solution of the Smoluchowski equation in the half space. A difference of the driving force acting on the colloids could be achieved by using two spherical particle types with differing diameters but equal mass density. First, we investigate how a difference in the channel slope affects the lane formation of the systems, after which we analyze the lanes that formed. We find that the large particles push the small particles to the walls, resulting in exclusively small particle lanes at the walls. This contrasts the equilibrium state, where depletion forces push the larger particles to the walls. Additionally, we have a closer look at the mechanisms by which the lanes form. Finally, we find system parameter values that foster lane formation to lay the foundation for an experimental realization of our proposed setup. To round this off, we give an exemplary calculation of the slope angle needed to get the experimental system into a state of lane order. With the examination of lane order in systems that are driven in parallel, we hope to deepen our understanding of nonequilibrium order phenomena.
我们研究了在重力作用下平行移动的胶体粒子非平衡系统中的车道形成。对于这种设置，可以设想在斜坡上进行通道的实验实现。我们采用布朗动力学算法，并基于半空间中Smoluchowski方程的解，用硬壁限制排斥性粒子。通过使用两种直径不同但质量密度相等的球形粒子类型，可以实现作用在胶体上的驱动力差异。首先，我们研究通道斜率的差异如何影响系统的车道形成，然后分析形成的车道。我们发现大粒子将小粒子推向壁面，导致壁面上仅形成小粒子车道。这与平衡状态形成对比，在平衡状态下，排空力将较大粒子推向壁面。此外，我们更仔细地研究了车道形成的机制。最后，我们找到了促进车道形成的系统参数值，为我们提出的设置的实验实现奠定基础。为了完善这一点，我们给出了使实验系统进入车道有序状态所需倾斜角的示例计算。通过研究平行驱动系统中的车道有序性，我们希望加深对非平衡有序现象的理解。
