Cluster-mediated driven transport in highly populated periodic structures

通过密集周期性结构的驱动粒子运动与细胞内过程以及在生物孔、合成通道、胶体单分子层、微流体装置和固体表面上的传输具有高度相关性。在大颗粒密度下，排除体积相互作用占优势，颗粒输运涉及合作运动。这些协同运动通常是由团簇来调节的，团簇是粒子在运动过程中保持在一起的集合。虽然在最近的实验中可以详细研究团簇动力学，但对它们缺乏很好的理论理解。通过结合分析和数值方法，我们的目的是解释团簇是如何在没有吸引人的相互作用的情况下在周期势中自发形成的，它们如何移动，以及它们如何在高度拥挤的系统中产生可测量的粒子流，在高度拥挤的系统中，干扰通常会缓解运动。将特别强调最近在布朗动力学中发现的孤子，它们对应于不同类型的团簇的周期性运动。它将探索孤子如何在依赖时间的周期驱动下形成和行为，以及周期结构中的缺陷和超出核心的粒子相互作用如何影响孤子运动。在该项目的进一步部分，我们将开发新的方法，利用这些方法可以在团簇运动的基础上有效地模拟高密度系统中的布朗动力学。在与实验小组现有合作的基础上，目标集中在可进行实验验证的问题上。我们的研究将为各种周期系统中的团簇驱动输运提供一个全面的理论理解。

Driven particle motion through densely populated periodic structures is of high relevance for intracellular processes as well as transport in biological pores, synthetic channels, colloidal monolayers, microfluidic devices, and on solid surfaces. At large particle densities, excluded volume interactions prevail and particle transport involves cooperative movements. These cooperative movements are often mediated by clusters, which are assemblies of particles that keep together during their motion. While cluster dynamics can be studied in detail in recent experiments, a good theoretical understanding of them is lacking. By combining analytical and numerical methods, our aim is to explain how clusters form spontaneously in periodic potentials even without attractive interaction, how they can move, and how they can give rise to measurable particle currents in highly crowded systems, where jamming typically mitigates motion. Particular emphasis will be given to the recently discovered solitons in Brownian dynamics, which correspond to periodic movements of clusters of different types. It shall be explored how the solitons form and behave under time-dependent periodic driving, and how imperfections in periodic structures and particle interactions beyond hardcore affect soliton motion. In a further part of the project, we will develop new methods by which Brownian dynamics in highly dense systems can be efficiently simulated on the basis of cluster movements. Building on existing cooperations with experimental groups, the objectives are focused on problems amenable to experimental verification. Our studies shall provide a comprehensive theoretical understanding of cluster-mediated driven transport in a large variety of periodic systems.