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One of the most famous observations in the history of science is Pasteur's discovery 150 years ago that crystals grown from a 50%/50% mixed solution of left-handed and right-handed chiral molecules (a "racemic" solution) can be either 100% left handed or 100% right handed. Such spontaneous chiral symmetry breaking had been found only in the formation of crystals until several years ago, when lcmrc researchers demonstrated it in a fluid layered liquid crystal phase. Now Center researchers have induced chiral segregation by application of an electric field to a liquid crystal phase of simpler molecules in which the response to field is enhanced if segregation occurs. In a liquid crystal cell of chiral molecules the separation of chiral components can be observed optically by viewing the cell between crossed polarizers, which, as the figure shows, dramatically reveals the formation of the chiral domains. The red and blue sticks indicate the average long axis direction of the liquid crystal molecules in the two domains, and their opposite handed orientation in the field (toward the reader). The theoretical description of this field-induced chirality reveals that this phenomenon should, in fact, be quite general, and that pressure, or even the cohesive forces holding solids and fluids together, can act as the electric field does.
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