SPONTANEOUS FORMATION OF MACROSCOPIC CHIRAL DOMAINS IN A FLUID SMECTIC PHASE OF ACHIRAL MOLECULES

A smectic liquid-crystal phase made from achiral molecules with bent c ores was found to have fluid layers that exhibit two spontaneous symme try-breaking instabilities: polar molecular orientational ordering abo ut the layer normal and molecular tilt. These instabilities combine to form a chiral layer structure with a handedness that depends on the s ign of the tilt. The bulk states are either antiferroelectric-racemic, with the layer polar direction and handedness alternating in sign fro m layer to layer, or antiferroelectric-chiral, which is of uniform lay er handedness. Both states exhibit an electric field-induced transitio n from antiferroelectric to ferroelectric.