Regensburg 2019 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 18: Fluid physics and turbulence

DY 18.2: Talk

Tuesday, April 2, 2019, 10:30–10:45, H20

Annihilation of Point Defect Pairs in Fluid Films — •Amine Missaoui¹, Kirsten Harth^1,2, and Stannarius Ralf¹ — ¹Otto von Guericke University Magdeburg, Inst. of Physics, ANP, Magdeburg, Germany. — ²Physics of Fluids and Max Planck Center for Complex Fluid Dynamics, University of Twente, Enschede, The Netherlands

Liquid crystals (LC) are one of the most valuable systems for studying the coarsening dynamics of topological defects. Disclinations in LC, pointlike defects, can be created and observed easily. They are excellent models to study fundamental properties of defect interactions, which are relevant in a wide range of research fields like cosmology or particle physics. In contrast to experiments in nematic LCs, which are 3D and much more complex, freely suspended smectic C films behave like quasi 2D polar nematics and are thus an ideal model system for studying quasi 2D systems.

We study defect annihilation in free-standing SmC freely suspended films experimentally. We prepare isolated defect pairs and we analyze their annihilation dynamics. The dynamics are strongly influenced by the orientation of the -1 defect with respect to the connecting axis, disorientation induces an orbital motion, dancing of the defects during the approach.