We consider a phenomenological continuum theory for an extensile, overdamped active nematic liquid crystal, applicable in the dense regime. Constructed from general principles, the theory is universal, with parameters independent of any particular microscopic realization. We show that it exhibits two distinct instabilities, one of which arises due to shear forces, and the other due to active torques. Both lead to the proliferation of defects. We focus on the active torque bend instability and find three distinct nonequilibrium steady states including a defect-ordered nematic in which +½ disclinations develop polar ordering. We characterize the phenomenology of these phases and identify the relationship of this theoretical description to experimental realizations and other theoretical models of active nematics.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5166704 | PMC |
| http://dx.doi.org/10.1039/c6sm00268d | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Irreversible dynamics of a continuum driven by active matter.
Phys Rev E
November 2024
Department of Physics, Duke University, Box 90305 Durham, North Carolina 27708-0305, USA.
We study the fluctuational behavior of overdamped elastic filaments (e.g., strings or rods) driven by active matter which induces irreversibility.
View Article and Find Full Text PDFSelf-consistent approach to the dynamics of excitation energy transfer in multichromophoric systems.
J Chem Phys
November 2024
Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
Article Synopsis
- Researchers have developed approximate methods to study exciton transport in molecular aggregates influenced by structured environments, moving beyond basic models that often become complex and hard to manage.
- They introduced a self-consistent Born approximation to better accommodate exciton-environment interactions and improve calculations of energy transfer dynamics in these systems.
- Their findings indicate that this new approach aligns well with more comprehensive models across various conditions, suggesting it effectively describes exciton behavior even in complex scenarios like the Fenna-Matthews-Olson complex.
Harmonically trapped inertial run-and-tumble particle in one dimension.
Phys Rev E
October 2024
S. N. Bose National Centre for Basic Sciences, Kolkata 700106, India.
We study the nonequilibrium stationary state of a one-dimensional inertial run-and-tumble particle (IRTP) trapped in a harmonic potential. We find that the presence of inertia leads to two distinct dynamical scenarios, namely, overdamped and underdamped, characterized by the relative strength of the viscous and the trap timescales. We also find that inertial nature of the active dynamics leads to the particle being confined in specific regions of the phase plane in the overdamped and underdamped cases, which we compute analytically.
View Article and Find Full Text PDFActive Brownian information engine: Self-propulsion induced colossal performance.
J Chem Phys
September 2024
Department of Chemistry and Center for Molecular and Optical Sciences and Technologies, Indian Institute of Technology Tirupati, Yerpedu 517619, Andhra Pradesh, India.
The information engine is a feedback mechanism that extorts work from a single heat bath using the mutual information earned during the measurement. We consider an overdamped active Ornstein-Uhlenbeck particle trapped in a 1D harmonic oscillator. The particle experiences fluctuations from an inherent thermal bath with a diffusion coefficient (D) and an active reservoir, with characteristic correlation time (τa) and strength (Da).
View Article and Find Full Text PDFVariational time reversal for free-energy estimation in nonequilibrium steady states.
Phys Rev E
August 2024
Department of Chemistry, University of California, Berkeley, California 94720, USA.
Studying the structure of systems in nonequilibrium steady states necessitates tools that quantify population shifts and associated deformations of equilibrium free-energy landscapes under persistent currents. Within the framework of stochastic thermodynamics, we establish a variant of the Kawasaki-Crooks equality that relates nonequilibrium free-energy corrections in overdamped Langevin systems to heat dissipation statistics along time-reversed relaxation trajectories computable with molecular simulation. Using stochastic control theory, we arrive at a general variational approach to evaluate the Kawasaki-Crooks equality and use it to estimate distribution functions of order parameters in specific models of driven and active matter, attaining substantial improvement in accuracy over simple perturbative methods.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!