Solitary wave propagation in antiferroelectric liquid crystal cells and the quadrupolar term in the interlayer interaction

Planar antiferroelectric liquid crystal (AFLC) cells exhibit propagating solitary waves. By measuring the retardation and the apparent tilt angle, we find that the conventional model for the solitary wave propagation in AFLCs is not generally applicable. The model being proposed here shows that the solitary wave propagation both along and normal to the smectic layer plane can be explained by a double well potential energy governing the relative orientations of the c directors in the adjacent smectic C layers with an energy barrier between the synclinic and the anticlinic states. The quadrupolar term of the interlayer interaction is found to be significantly large in a pure AFLC.