Rønning, Jonas; Renaud, Julian BISTA; Doostmohammadi, Amin; Angheluta, Luiza
Polar active matter of self-propelled particles sustain spontaneous flows through the full-integer topological defects. We study theoretically the incompressible flow profiles around ±1 defects induced by polar and dipolar active forces. We show that dipolar forces induce vortical flows around the +1 defect, while the flow around the −1 defect has an 8-fold rotational symmetry. The vortical flow changes its chirality near the +1 defect core in the absence of the friction with a substrate. We show analytically that the flow induced by polar active forces is vortical near the +1 defect and is 4-fold symmetric near the −1 defect, while it becomes uniform in the far-field. For a pair of oppositely charged defects, this polar flow contributes to a mutual interaction force that depends only on the orientation of the defect pair relative to the background polarization, and that enhances defect pair annihilation. This is in contradiction with the effect of dipolar active forces which decay inversely proportional with the defect separation distance. As such, our analyses reveals a long-ranged mechanism for the pairwise interaction between topological defects in polar active matter.
J. Rø and L. A. acknowledge support from the Research Council of Norway through the Center of Excellence funding scheme, Project No. 262644 (PoreLab). A. D. acknowledges funding from the Novo Nordisk Foundation (grant No. NNF18SA0035142 and NERD grant No. NNF21OC0068687), Villum Fonden Grant no. 29476, and the European Union via the ERC-Starting Grant PhysCoMeT. Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them.
Rønning J, Renaud JB, Doostmohammadi A, Angheluta L. Spontaneous flows and dynamics of full-integer topological defects in polar active matter. Soft Matter. 2023. doi:10.1039/d3sm00316g
Rønning, J., Renaud, J. B., Doostmohammadi, A., & Angheluta, L. (2023). Spontaneous flows and dynamics of full-integer topological defects in polar active matter. Soft Matter. Royal Society of Chemistry. https://doi.org/10.1039/d3sm00316g
Rønning, Jonas, Julian B Renaud, Amin Doostmohammadi, and Luiza Angheluta. “Spontaneous Flows and Dynamics of Full-Integer Topological Defects in Polar Active Matter.” Soft Matter. Royal Society of Chemistry, 2023. https://doi.org/10.1039/d3sm00316g.
J. Rønning, J. B. Renaud, A. Doostmohammadi, and L. Angheluta, “Spontaneous flows and dynamics of full-integer topological defects in polar active matter,” Soft Matter. Royal Society of Chemistry, 2023.
Rønning J, Renaud JB, Doostmohammadi A, Angheluta L. 2023. Spontaneous flows and dynamics of full-integer topological defects in polar active matter. Soft Matter.
Rønning, Jonas, et al. “Spontaneous Flows and Dynamics of Full-Integer Topological Defects in Polar Active Matter.” Soft Matter, Royal Society of Chemistry, 2023, doi:10.1039/d3sm00316g.
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