Scalar φ4 field theory for active-particle phase separation

Raphael Wittkowski (), Adriano Tiribocchi, Joakim Stenhammar, Rosalind J. Allen, Davide Marenduzzo and Michael E. Cates
Additional contact information
Raphael Wittkowski: SUPA, School of Physics and Astronomy, University of Edinburgh
Adriano Tiribocchi: SUPA, School of Physics and Astronomy, University of Edinburgh
Joakim Stenhammar: SUPA, School of Physics and Astronomy, University of Edinburgh
Rosalind J. Allen: SUPA, School of Physics and Astronomy, University of Edinburgh
Davide Marenduzzo: SUPA, School of Physics and Astronomy, University of Edinburgh
Michael E. Cates: SUPA, School of Physics and Astronomy, University of Edinburgh

Nature Communications, 2014, vol. 5, issue 1, 1-9

Abstract: 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.

Date: 2014
References: Add references at CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
https://www.nature.com/articles/ncomms5351 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:5:y:2014:i:1:d:10.1038_ncomms5351

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/ncomms5351

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().