Dynamical patterns in nematic active matter on a sphere

Silke Henkes, M. Cristina Marchetti, Rastko Sknepnek

Research output: Contribution to journalArticle

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Abstract

Using simulations of self-propelled agents with short-range repulsion and nematic alignment, we explore the dynamical phases of a dense active nematic confined to the surface of a sphere. We map the non-equilibrium phase diagram as a function of curvature, alignment strength and activity. Our model reproduces several phases seen in recent experiments on active microtubule bundles confined the surfaces of vesicles. At low driving, we recover the equilibrium nematic ground state with four +1/2 defects. As the driving is increased, geodesic forces drive the transition to a polar band wrapping around an equator, with large empty spherical caps corresponding to two +1 defects at the poles. Upon further increasing activity, the bands fold onto themselves, and the system eventually transitions to a turbulent state marked by the proliferation of pairs of topological defects. We highlight the key role of the nematic persistence length in controlling pattern formation in these confined systems with positive Gaussian curvature.
Original languageEnglish
Article number042605
Pages (from-to)1-12
Number of pages12
JournalPhysical Review. E, Statistical, Nonlinear and Soft Matter Physics
Volume97
Issue number4
Early online date16 Apr 2018
DOIs
Publication statusPublished - Apr 2018

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defects
alignment
curvature
spherical caps
Alignment
Defects
equators
Equator
Topological Defects
bundles
Microtubules
Positive Curvature
Total curvature
Vesicles
poles
Pattern Formation
Proliferation
phase diagrams
Persistence
Phase Diagram

Cite this

Dynamical patterns in nematic active matter on a sphere. / Henkes, Silke; Marchetti, M. Cristina; Sknepnek, Rastko.

In: Physical Review. E, Statistical, Nonlinear and Soft Matter Physics, Vol. 97, No. 4, 042605, 04.2018, p. 1-12.

Research output: Contribution to journalArticle

Henkes, Silke ; Marchetti, M. Cristina ; Sknepnek, Rastko. / Dynamical patterns in nematic active matter on a sphere. In: Physical Review. E, Statistical, Nonlinear and Soft Matter Physics. 2018 ; Vol. 97, No. 4. pp. 1-12.
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