Simultaneous Phase Separation and Pattern Formation in Chiral Active Mixtures

Demian Levis; Benno Liebchen

doi:10.1103/physreve.100.012406

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arXiv · 1901.08496

Simultaneous Phase Separation and Pattern Formation in Chiral Active Mixtures

Demian Levis·Benno Liebchen

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Abstract

Chiral active particles, or self-propelled circle swimmers, from sperm cells to asymmetric Janus colloids, form a rich set of patterns, which are different from those seen in linear swimmers. Such patterns have mainly been explored for identical circle swimmers, while real-world circle swimmers, typically possess a frequency distribution. Here we show that even the simplest mixture of (velocity-aligning) circle swimmers with two different frequencies, hosts a complex world of superstructures: The most remarkable example comprises a microflock pattern, formed in one species, while the other species phase separates and forms a macrocluster, coexisting with a gas phase. Here, one species microphase-separates and selects a characteristic length scale, whereas the other one macrophase separates and selects a density. A second notable example, here occurring in an isotropic system, are patterns comprising two different characteristic length scales, which are controllable via frequency and swimming speed of the individual particles.

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Demian Levis, Benno Liebchen. 2019-01-24. Simultaneous Phase Separation and Pattern Formation in Chiral Active Mixtures. https://doi.org/10.1103/physreve.100.012406

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