Mixtures of active and passive particles are predicted to exhibit a variety of nonequilibrium phases. Here we report a dynamic clustering phase in mixtures of colloids and motile bacteria. We show that colloidal clustering results from a balance between bond breaking due to persistent active motion and bond stabilization due to torques that align active particle velocity tangentially to the passive particle surface. Furthermore, dynamic clustering spans a broad regime between diffusivity-based and motility-induced phase separation that subsumes typical bacterial motility parameters.
@article{arxiv.2110.02294,
title = {Dynamic clustering of passive colloids in dense suspensions of motile bacteria},
author = {Shreyas Gokhale and Junang Li and Alexandre Solon and Jeff Gore and Nikta Fakhri},
journal= {arXiv preprint arXiv:2110.02294},
year = {2022}
}