Archive ouverte HAL – A nonequilibrium force can stabilize 2D active nematics

Ananyo Maitra 1, * Pragya Srivastava 2 M. Cristina Marchetti 3 Juho Lintuvuori 4 Sriram Ramaswamy 5, 6 Martin Lenz 1, 7, *

Proceedings of the National Academy of Sciences of the United States of America , National Academy of Sciences, 2018, 115 (27), pp.6934-6939

Suspensions of actively driven anisotropic objects exhibit distinctively nonequilibrium behaviors, and current theories predict that they are incapable of sustaining orientational order at high activity. By contrast, here we show that nematic suspensions on a substrate can display order at arbitrarily high activity due to a previously unreported, potentially stabilizing active force. This force moreover emerges inevitably in theories of active orientable fluids under geometric confinement. The resulting nonequilibrium ordered phase displays robust giant number fluctuations that cannot be suppressed even by an incompressible solvent. Our results apply to virtually all experimental assays used to investigate the active nematic ordering of self-propelled colloids, bacterial sus-pensions, and the cytoskeleton and have testable implications in interpreting their nonequilibrium behaviors.

  • 1. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques
  • 2. Theoretical Physics of Biology Laboratory
  • 3. Department of Physics [Syracuse]
  • 4. LOMA - Laboratoire Ondes et Matière d'Aquitaine
  • 5. TIFR - Tata Institute of Fundamental Research [Hyderabad]
  • 6. Centre for Condensed Matter Theory [Bangalore]
  • 7. MSE2 - Multiscale Materials Science for Energy and Environment