Collective and tracer dynamics in single-file transport through periodic structures

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Single-file transport refers to the motion in a many-particle system,where the particles cannot overtake each other because of theirinteractions and spatial confinements. In this project the stochasticBrownian motion of diffusion agents with single-file character isconsidered. This type of motion occurs ubiquitously in nature andtechnology whenever particles are forced to move through narrow poreswith diameters only slightly larger than the particle size. Prominentexamples are diffusion in crystalline aluminosilicates (zeolites),membrane channels, nanotubes, channels in micro- and nanofluidicdevices, as well as colloid motions in experiments with advancedoptical and magnetic manipulation techniques. While these and otherexamples typically involve periodic structures, theoretical work hasmainly focused so far on spatially homogeneous systems with respect tothe anomalous subdiffusion of a single tagged particle (tracer), or onoversimplified discrete systems with respect to collective transportproperties. An understanding of tracer and collective dynamics insingle-file Brownian motion through periodic structures is stillmissing. In this bilateral project, we aim to fill this gap bydeveloping paradigmatic models and methods for their analysis. Thisincludes both analytical approaches and efficient simulationtechniques. Our specific objectives are to develop a full theory forparticles behaving like hard spheres, which will serve as a basis forfurther investigations of other types of short-range particleinteractions and systems with different types of particles.Particular emphasis will be put on the possibility to probe differentphases of collective behavior by observing a tracer's transitionkinetics between sites in the periodic structures. Resultsobtained for idealized one-dimensional single-file transport will bechecked with respect to their validity for corresponding fullthree-dimensional pore structures.