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arXiv · 2506.13140

Density-Independent transient caging in the high-density phase of motility-induced phase separation

Toranosuke Umemura·Issei Sakai·Takuma Akimoto
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Abstract

We investigate the nonequilibrium dynamics of active matter using a two-dimensional active Brownian particles model. In these systems, self-propelled particles undergo motility-induced phase separation (MIPS), spontaneously segregating into dense and dilute phases. We find that in the high-density phase, local particle mobility exhibits transient caging, with diffusivity remaining unchanged despite variations in the global system density. As global density increases further, the system undergoes a transition to a solid-like state through an intermediate regime with pronounced dynamical arrest. Our findings identify a distinct high-density regime characterized by transient caging and dynamical slowing down in a monodisperse active system, shedding new light on the connection between MIPS and nonequilibrium arrest.

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Toranosuke Umemura, Issei Sakai, Takuma Akimoto. 2025-06-16. Density-Independent transient caging in the high-density phase of motility-induced phase separation. https://doi.org/10.1103/vyzm-8f6p

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