A particle-field approach bridges phase separation and collective motion in active matter
- Others:
- Laboratoire Jean Alexandre Dieudonné (JAD) ; Université Nice Sophia Antipolis (1965 - 2019) (UNS) ; COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)
- Institute for Physics and Astronomy, University of Potsdam, Potsdam, Germany, D-14476
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Laboratoire de Physique Théorique et Modélisation (LPTM - UMR 8089) ; Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)
- CY Cergy Paris Université (CY)
- Université de Cergy Pontoise (UCP) ; Université Paris-Seine
Description
Abstract Whereas self-propelled hard discs undergo motility-induced phase separation, self-propelled rods exhibit a variety of nonequilibrium phenomena, including clustering, collective motion, and spatio-temporal chaos. In this work, we present a theoretical framework representing active particles by continuum fields. This concept combines the simplicity of alignment-based models, enabling analytical studies, and realistic models that incorporate the shape of self-propelled objects explicitly. By varying particle shape from circular to ellipsoidal, we show how nonequilibrium stresses acting among self-propelled rods destabilize motility-induced phase separation and facilitate orientational ordering, thereby connecting the realms of scalar and vectorial active matter. Though the interaction potential is strictly apolar, both, polar and nematic order may emerge and even coexist. Accordingly, the symmetry of ordered states is a dynamical property in active matter. The presented framework may represent various systems including bacterial colonies, cytoskeletal extracts, or shaken granular media.
Abstract
International audience
Additional details
- URL
- https://hal.archives-ouvertes.fr/hal-03383357
- URN
- urn:oai:HAL:hal-03383357v1
- Origin repository
- UNICA