标题： 受限手性活性物质中的辫状混合 显示英文标题

标题： Braided mixing in confined chiral active matter

摘要： 高效的流体混合在许多实际应用中对于实现均匀性至关重要。然而，对于微观系统来说，由于低雷诺数的原因，扩散和湍流都是无效的混合方法，因此通常采用主动搅拌或通过几何边界效应诱导湍流。在这里，我们研究了一种修改后的手性Vicsek模型，在该模型中，活性微泳者作为移动棒来搅拌周围的基质。我们研究了由限制、手性运动和对齐相互作用之间的相互作用所形成的模式中的混合程度。这种混合通过考虑粒子的时空轨迹的纠缠来计算，这些轨迹形成一个辫子。优化这个辫子的有限时间编织指数，可以得出系统的组成部分参数，表明由局部稳定涡旋液滴和有序振荡相组成的图案实现了最高的混合程度。 显示英文摘要

摘要： Efficient mixing of fluids is essential in many practical applications to achieve homogeneity. For microscopic systems, however, both diffusion and turbulence are ineffective methods to achieve chaotic mixing due to the low Reynolds number, hence either active stirring or inducing turbulence through geometric boundary effects are generally implemented. Here, we study a modified chiral Vicsek model, where active microswimmers act as moving rods, stirring the surrounding substrate. We study the degree of mixing in the patterns formed by interplay between confinement, chiral motion and alignment interactions. This mixing is computed by considering the entanglement of spacetime trajectories of the particles, which forms a braid. Optimising the finite-time braiding exponent of this braid then yields a set of constituent parameters of the system, showing that a pattern consisting of a local stable vortex droplet and an ordered oscillating phase achieves the highest degree of mixing.