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Ordered structures formed by nematic topological defects and their transformation with changing the Euler
P V Dolganov1, N A Spiridenko1, V K Dolganov1
1Osipyan <a href="https://ror.org/00ezjkn15">Institute of Solid State Physics</a> RAS, 142432 Chernogolovka, Moscow Region, Russia.
Physical Review. E
|September 19, 2024
Summary
Researchers studied topological defects in nematic films, observing how defect chains transform and annihilate. Their dynamics differ from standard coarsening in 2D and 3D systems.
Area of Science:
- Physics
- Materials Science
Background:
- Topological defects are crucial in understanding the behavior of materials like nematic liquid crystals.
- Competing surface anchoring conditions can induce topological defects at interfaces.
Purpose of the Study:
- To investigate the dynamics and cooperative rearrangement of ordered chain structures formed by topological defects.
- To analyze the transformation and annihilation processes of these defect chains in nematic films.
Main Methods:
- Preparation of ordered chain structures from topological defects with opposite charges.
- Studying topological defects in nematic films by inducing changes in Euler characteristic via temperature.
- Observing defect emergence due to competing surface anchoring at nematic-isotropic and nematic-solid interfaces.
Main Results:
- Ordered chain structures, or "necklaces" of defects, were successfully prepared and their dynamics investigated.
- A transformation from circular defect chains to single defects, and finally to a defect-free state, was observed with changing nematic geometry.
- The temporal evolution of defect annihilation in these chains showed distinct behavior compared to coarsening in 2D and 3D geometries.
Conclusions:
- The study reveals unique dynamics of topological defect chains in nematic films.
- The observed annihilation processes deviate from conventional coarsening phenomena, highlighting the influence of chain structure.
- Understanding these defect dynamics is key for controlling material properties in confined geometries.
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