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Updated: Feb 14, 2026
08:37
Forming, Confining, and Observing Microtubule-Based Active Nematics
Published on: January 13, 2023
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Low-noise phase of a two-dimensional active nematic system
Suraj Shankar1,2, Sriram Ramaswamy3, M Cristina Marchetti1
1Physics Department and Syracuse Soft & Living Matter Program, Syracuse University, Syracuse, New York 13244, USA.
Physical Review. E
|February 17, 2018
Summary
Self-driven apolar particles form an active nematic phase. Giant number fluctuations persist due to activity, preventing phase separation and leading to quasi-long-ranged order.
Area of Science:
- Physics
- Soft Matter Physics
- Statistical Mechanics
Background:
- Active matter systems exhibit emergent collective behaviors.
- Apolar particles can self-organize into nematic phases.
- Understanding fluctuations is crucial in condensed matter systems.
Purpose of the Study:
- To investigate the two-dimensional fluctuating active nematic phase.
- To analyze the role of noise and nonlinearities on particle organization.
- To determine the nature of orientational order and density fluctuations.
Main Methods:
- Dynamical renormalization group (DRG) approach.
- Coarse-grained hydrodynamic description.
- Symmetry analysis of nonlinear terms.
Main Results:
- The system exhibits quasi-long-ranged orientational order beyond a crossover scale.
- Activity is found to be "dangerously irrelevant" in the linearized description.
- Giant number fluctuations persist with finite-size effects and nonuniversal scaling.
- Nonlinear active currents induce power-law correlations in density.
Conclusions:
- Active nematic phases display complex fluctuation dynamics.
- Macroscopic phase separation is prevented by nonlinear effects.
- The study provides insights into the statistical mechanics of active matter.
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