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Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
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Giant director fluctuations in liquid crystal drops
Alexis de la Cotte1, Olaf Stenull1, Sophie Ettinger1
1Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Physical Review. E
|May 20, 2022
Summary
Giant spatiotemporal orientational fluctuations were discovered in nematic liquid crystal drops. These fluctuations arise from a critical mode in the hedgehog defect
Area of Science:
- Soft Matter Physics
- Liquid Crystal Science
- Complex Fluids
Background:
- Nematic liquid crystals exhibit orientational order.
- Defects, such as the hedgehog, are key topological structures.
- Understanding defect stability is crucial for liquid crystal applications.
Purpose of the Study:
- To discover and elucidate giant spatiotemporal orientational fluctuations.
- To investigate the stability of radial hedgehog defects in liquid crystal drops.
- To correlate theoretical predictions with experimental observations.
Main Methods:
- Polarized optical microscopy for experimental observation.
- Calculation of the Frank elastic free energy eigenspectrum.
- Theoretical modeling of nematic drops with a central hedgehog defect.
Main Results:
- Discovery of giant spatiotemporal orientational fluctuations near the hedgehog core.
- Identification of a critical mode in the defect's excitation spectrum.
- Demonstration of radial hedgehog instability for specific radius ratios (μ > μc).
Conclusions:
- The radial hedgehog defect is unstable above a critical radius ratio.
- A critical mode drives large-amplitude director fluctuations observed experimentally.
- Experimental data collapse validates theoretical predictions and estimates defect core size.
