Low-noise phase of a two-dimensional active nematic system

Suraj Shankar, Sriram Ramaswamy, M Cristina Marchetti

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We consider a collection of self-driven apolar particles on a substrate that organize into an active nematic phase at sufficiently high density or low noise. Using the dynamical renormalization group, we systematically study the two-dimensional fluctuating ordered phase in a coarse-grained hydrodynamic description involving both the nematic director and the conserved density field. In the presence of noise, we show that the system always displays only quasi-long-ranged orientational order beyond a crossover scale. A careful analysis of the nonlinearities permitted by symmetry reveals that activity is dangerously irrelevant over the linearized description, allowing giant number fluctuations to persist although now with strong finite-size effects and a nonuniversal scaling exponent. Nonlinear effects from the active currents lead to power-law correlations in the density field, thereby preventing macroscopic phase separation in the thermodynamic limit.

Original languageEnglish (US)
Article number012707
JournalPhysical Review E
Volume97
Issue number1
DOIs
StatePublished - Jan 29 2018

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Phase Noise
low noise
Finite Size Effects
Scaling Exponent
Phase Separation
Nonlinear Effects
Thermodynamic Limit
display devices
Renormalization Group
Crossover
Hydrodynamics
crossovers
Power Law
nonlinearity
hydrodynamics
Substrate
exponents
Nonlinearity
Fluctuations
Symmetry

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Condensed Matter Physics

Cite this

Low-noise phase of a two-dimensional active nematic system. / Shankar, Suraj; Ramaswamy, Sriram; Marchetti, M Cristina.

In: Physical Review E, Vol. 97, No. 1, 012707, 29.01.2018.

Research output: Contribution to journalArticle

Shankar, Suraj ; Ramaswamy, Sriram ; Marchetti, M Cristina. / Low-noise phase of a two-dimensional active nematic system. In: Physical Review E. 2018 ; Vol. 97, No. 1.
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