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IRG1, February 28 at 4PM, MRL Room 2053, Prof. Tom C. Lubensky Department of Physics and Astronomy University of Pennsylvania, Philadelphia, PA 19104 "Topological Defects, Interactions, and Chaining in Nematic Emulsions" Broken symmetry with its accompanying rigidities, low-energy modes, and topological defects is a unifying concept in physics. Liquid crystals have proven to be particularly fruitful laboratories for the study of various consequences of broken symmetry. They provide, in particular, visually striking confirmation of the existence of topological defects. A new class of liquid-crystal emulsions, in which surfactant coated water droplets are dispersed in an anisotropic nematic liquid crystalline host, will serve as the basis for the discussion of topological defects in general and disclination and hedghog defects in nematic liquid crystals in particular. Properties of these emulsions, such as chaining of water droplets and long term stability, will be explained by hedgehog configurations around water droplets and companion hedghog defects pulled out of the nematic to preserve overall hedghog charge neutrality. |
