Scalar phi^4 field theory for active-particle phase separation
(2014) In Nature Communications 5(Published online 10 July 2014).- Abstract
- Recent theories predict phase separation among orientationally disordered active particles whose propulsion speed decreases rapidly enough with density. Coarse-grained models of this process show time-reversal symmetry (detailed balance) to be restored for uniform states, but broken by gradient terms; hence, detailed-balance violation is strongly coupled to interfacial phenomena. To explore the subtle generic physics resulting from such coupling, we here introduce ‘Active Model B’. This is a scalar φ4 field theory (or phase-field model) that minimally violates detailed balance via a leading-order square-gradient term. We find that this additional term has modest effects on coarsening dynamics, but alters the static phase diagram by... (More)
- Recent theories predict phase separation among orientationally disordered active particles whose propulsion speed decreases rapidly enough with density. Coarse-grained models of this process show time-reversal symmetry (detailed balance) to be restored for uniform states, but broken by gradient terms; hence, detailed-balance violation is strongly coupled to interfacial phenomena. To explore the subtle generic physics resulting from such coupling, we here introduce ‘Active Model B’. This is a scalar φ4 field theory (or phase-field model) that minimally violates detailed balance via a leading-order square-gradient term. We find that this additional term has modest effects on coarsening dynamics, but alters the static phase diagram by creating a jump in (thermodynamic) pressure across flat interfaces. Both results are surprising, since interfacial phenomena are always strongly implicated in coarsening dynamics but are, in detailed-balance systems, irrelevant for phase equilibria. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4580824
- author
- Wittkowski, Raphael ; Tiribocchi, Adriano ; Stenhammar, Joakim LU ; Allen, Rosalind ; Marenduzzo, Davide and Cates, Michael
- publishing date
- 2014
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Nature Communications
- volume
- 5
- issue
- Published online 10 July 2014
- article number
- 4351
- publisher
- Nature Publishing Group
- external identifiers
-
- wos:000340615500042
- scopus:84904327902
- ISSN
- 2041-1723
- DOI
- 10.1038/ncomms5351
- language
- English
- LU publication?
- no
- id
- 6a8f62dc-5d10-4d74-b83d-7dfa8cd25249 (old id 4580824)
- alternative location
- https://arxiv.org/abs/1311.1256
- http://www.nature.com/ncomms/2014/140710/ncomms5351/full/ncomms5351.html
- date added to LUP
- 2016-04-01 14:31:17
- date last changed
- 2022-04-22 03:30:03
@article{6a8f62dc-5d10-4d74-b83d-7dfa8cd25249,
abstract = {{Recent theories predict phase separation among orientationally disordered active particles whose propulsion speed decreases rapidly enough with density. Coarse-grained models of this process show time-reversal symmetry (detailed balance) to be restored for uniform states, but broken by gradient terms; hence, detailed-balance violation is strongly coupled to interfacial phenomena. To explore the subtle generic physics resulting from such coupling, we here introduce ‘Active Model B’. This is a scalar φ4 field theory (or phase-field model) that minimally violates detailed balance via a leading-order square-gradient term. We find that this additional term has modest effects on coarsening dynamics, but alters the static phase diagram by creating a jump in (thermodynamic) pressure across flat interfaces. Both results are surprising, since interfacial phenomena are always strongly implicated in coarsening dynamics but are, in detailed-balance systems, irrelevant for phase equilibria.}},
author = {{Wittkowski, Raphael and Tiribocchi, Adriano and Stenhammar, Joakim and Allen, Rosalind and Marenduzzo, Davide and Cates, Michael}},
issn = {{2041-1723}},
language = {{eng}},
number = {{Published online 10 July 2014}},
publisher = {{Nature Publishing Group}},
series = {{Nature Communications}},
title = {{Scalar phi^4 field theory for active-particle phase separation}},
url = {{http://dx.doi.org/10.1038/ncomms5351}},
doi = {{10.1038/ncomms5351}},
volume = {{5}},
year = {{2014}},
}