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Related papers: Defect unbinding in active nematics

200 papers

We construct the equations of motion for the coupled dynamics of order parameter and concentration for the nematic phase of driven particles on a solid surface, and show that they imply (i) giant number fluctuations, with a standard…

Soft Condensed Matter · Physics 2009-11-07 Sriram Ramaswamy , R. Aditi Simha , John Toner

The transition from complex-periodic to chaotic behavior is investigated in oscillatory media supporting spiral waves. We find turbulent regimes characterized by the spontaneous nucleation, proliferation and erratic motion of…

chao-dyn · Physics 2009-10-31 Andrei Goryachev , Hugues Chate' , Raymond Kapral

Active nematic fluids confined in narrow channels generate spontaneous flows when the activity is sufficiently intense. Recently, it was shown that if the molecular anchoring at the channel walls is conflicting flows are initiated even in…

Soft Condensed Matter · Physics 2021-11-02 C. Rorai , F. Toschi , I. Pagonabarraga

The point defect thermodynamics in a general family of binary compounds, including B2 compounds as a specific representative, are classified by way of two non-trivial energy parameters. The scheme is applied to published ab initio defect…

Materials Science · Physics 2015-03-13 Michael Leitner

The problem of low Reynolds number turbulence in active nematic fluids is theoretically addressed. Using numerical simulations I demonstrate that an incompressible turbulent flow, in two-dimensional active nematics, consists of an ensemble…

Soft Condensed Matter · Physics 2015-08-04 Luca Giomi

We numerically investigate the effect of a periodic array of asymmetric obstacles in a two-dimensional active nematic. We find that activity in conjunction with the asymmetry leads to a ratchet effect or unidirectional flow of the fluid…

Soft Condensed Matter · Physics 2024-03-25 Cody D. Schimming , C. J. O. Reichhardt , C. Reichhardt

The presence of defects in solids formed by active particles breaks their discrete translational symmetry. As a consequence, many of their properties become space-dependent and different from those characterizing perfectly ordered…

Statistical Mechanics · Physics 2023-11-08 Lorenzo Caprini , Hartmut Löwen , Umberto Marini Bettolo Marconi

An analysis of the IR absorbance for the segmented functional groups of liquid crystal dimers: mesogen and linker, enabled the orientation order to be determined and information about the dipole interactions in the nematic and twist-bend…

Soft Condensed Matter · Physics 2026-05-19 Antoni Kocot , Barbara Loska , Yuki Arakawa , Katarzyna Merkel

Recent studies have shown that packings of cells, both eukaryotic cellular tissues and growing or swarming bacterial colonies, can often be understood as active nematic fluids. A key property of volume-conserving active nematic model…

Soft Condensed Matter · Physics 2022-05-12 Fabian Jan Schwarzendahl , Daniel A. Beller

Solids built out of active components can exhibit non-reciprocal elastic coefficients that give rise to non-Hermitian wave phenomena. Here, we investigate non-Hermitian effects present at the boundary of two-dimensional active elastic media…

Soft Condensed Matter · Physics 2020-09-16 Colin Scheibner , William T. M. Irvine , Vincenzo Vitelli

We study the nonequilibrium dynamics leading to the formation of topological defects in a symmetry-breaking phase transition of a quantum scalar field with \lambda\Phi^4 self-interaction in a spatially flat, radiation-dominated…

General Relativity and Quantum Cosmology · Physics 2009-10-31 G. J. Stephens , E. A. Calzetta , B. L. Hu , S. A. Ramsey

This paper is the second in a pair treating a new lattice model for nematic media. In addition to the familiar isotropic (I) and nematically ordered (N) phases, the phase diagram established in the previous paper (Paper I) contains a new,…

Condensed Matter · Physics 2009-10-28 John Toner , Paul E. Lammert , Daniel S. Rokhsar

We show that back-flow, the coupling between the order parameter and the velocity fields, has a significant effect on the motion of defects in nematic liquid crystals. In particular the defect speed can depend strongly on the topological…

Soft Condensed Matter · Physics 2007-05-23 Geza Toth , Colin Denniston , Julia M. Yeomans

The interaction between two disks immersed in a 2D nematic is investigated (i) analitically using the tensor order parameter formalism for the nematic configuration around isolated disks and (ii) numerically using finite element methods…

Soft Condensed Matter · Physics 2009-11-07 M. Tasinkevych , N. M. Silvestre , P. Patricio , M. M. Telo da Gama

We report numerical results for the hydrodynamics of inhomogeneous lyotropic and extensile active nematic gels. By simulating the coupled Cahn-Hilliard, Navier-Stokes, and Beris-Edwards equation for the evolution of the composition, flow…

Soft Condensed Matter · Physics 2023-01-06 Renato Assante , Dom Corbett , Davide Marenduzzo , Alexander Morozov

Biological surfaces, such as developing epithelial tissues, exhibit in-plane polar or nematic order and can be strongly curved. Recently, integer (+1) topological defects have been identified as morphogenetic hotspots in living systems.…

Soft Condensed Matter · Physics 2024-06-18 Rushikesh Shinde , Raphaël Voituriez , Andrew Callan-Jones

Inspired by epithelial morphogenesis, we consider a minimal model for the shaping of a surface driven by $p$-atic topological defects. We show that a positive (negative) defect can dynamically generate a (hyperbolic) cone whose shape…

Soft Condensed Matter · Physics 2023-03-02 Farzan Vafa , L. Mahadevan

The collective effects of microswimmers in active suspensions result in active turbulence, a spatiotemporally chaotic dynamics at mesoscale, which is characterized by the presence of vortices and jets at scales much larger than the…

Fluid Dynamics · Physics 2020-02-24 Moritz Linkmann , M. Cristina Marchetti , Guido Boffetta , Bruno Eckhardt

Continuum models of active nematic gels have proved successful to describe a number of biological systems consisting of a population of rodlike motile subunits in a fluid environment. However, in order to get a thorough understanding of the…

Soft Condensed Matter · Physics 2023-05-03 Stefano Turzi

We present experimental evidence that the motion of point defects in thermal convection patterns in an inclined fluid layer is well-described by Tsallis statistics with an entropic index $q \approx 1.5$. The dynamical properties of the…

Statistical Mechanics · Physics 2007-05-23 Karen E. Daniels , Christian Beck , Eberhard Bodenschatz