Two Kinds of Boundary Motions in Thin Ferroelectric Smectic C^* Liquid Crystals

Abstract

The switching process in thin ferroelectric liquid crystal cells under low frequency triangular wave is studied. It is pointed out that there exist three switching processes which are classified into two kinds of boundary motions. One is attributed to an interior 2π disclination motion without changing surface molecular orientation, while the other to a reversion of C-directors on a top and bottom surface which may accompany a surface disclination motion. The field induced motion of a disclination loop separating two kinds of twisted states is discussed by taking into account a structural asymmetry of ±2 π wedge disclinations.