Three-Dimensional Active Defect Loops

Abstract

We describe the flows and morphological dynamics of topological defect lines and loops in three-dimensional active nematics and show, using theory and numerical modelling, that they are governed by the local profile of the orientational order surrounding the defects. Analysing a continuous span of defect loop profiles, ranging from radial and tangential twist to wedge $\pm 1/2$ profiles, we show that the distinct geometries can drive material flow perpendicular or along the local defect loop segment, whose variation around a closed loop can lead to net loop motion, elongation or compression of shape, or buckling of the loops. We demonstrate a correlation between local curvature and the local orientational profile of the defect loop, indicating dynamic coupling between geometry and topology. To address the general formation of defect loops in three dimensions, we show their creation via bend instability from different initial elastic distortions.

arXiv comment12 pages, 4 figures

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Cited by in corpus (25)

• Topological active matter
• Active Turbulence
• Geometry and mechanics of disclination lines in 3D nematic liquid crystals
• Flow states and transitions of an active nematic in a three dimensional channel
• Morphology of active deformable 3D droplets
• Singularity identification for the characterization of topology, geometry, and motion of nematic disclination lines
• Active extensile stress promotes 3D director orientations and flows
• Morphodynamics of Active Nematic Fluid Surfaces
• Intrinsic Geometry and Director Reconstruction for Three-Dimensional Liquid Crystals
• Defect Line Coarsening and Refinement in Active Nematics
• Binding self-propelled topological defects in active turbulence
• Kinematics and dynamics of disclination lines in three-dimensional nematics
• Helical Flow States in Active Nematics
• Scaling and spontaneous symmetry restoring of topological defect dynamics in liquid crystal
• Geometry of Bend: Singular Lines and Defects in Twist-Bend Nematics
• Defect Loops in Three-Dimensional Active Nematics as Active Multipoles
• Anisotropic disclination cores in nematic liquid crystals modelled by a self consistent molecular field theory
• Chirality, anisotropic viscosity and elastic anisotropy in three-dimensional active nematic turbulence
• Contact Topology and the Classification of Disclination Lines in Cholesteric Liquid Crystals
• Coexistence of defect morphologies in three dimensional active nematics
• Frank-Read Mechanism in Nematic Liquid Crystals
• Active Nematic Multipoles: Flow Responses and the Dynamics of Defects and Colloids
• Analytical model for the motion and interaction of two-dimensional active nematic defects
• Vortex line entanglement in active Beltrami flows
• Simulations of Three-dimensional Nematic Guidance of Microswimmers