A Soliton Model for the Chevron Layer Structure in SmC* Liquid Crystals

In this work, a simple explanation is given for the chevron layer structure which has been observed in SmC* phase. A phenomenological elastic free energy concerned with layer distortion, c−director deformation, and their coupling is proposed to discuss the layer structure of them. It will be shown that there exists a soliton solution corresponding to the chevron structure. The transition layer thickness of the chevron is theoretically estimated as the penetration length (∼molecular length)/molecular tilt angle. In similar to the kinked layer structure, the c-director rotation angle is also found to show a soliton-like behaviour within the transition region. In addition, the existence of the selective pre-tilt at the bounding surface is explained in the relation with the chevron structure.