Does the disclination line exist in a homogeneously aligned SmCa* cell?

Abstract

Abstract We have studied the structure of the disclination lines observed in the antiferroelectric SmCA phase of thick homogeneously aligned cells. Comparing the period of these lines with the helical pitch determined by means of selective reflection and laser beam diffraction, we concluded that the period of the disclination lines corresponds to half the pitch. We show that a pair of π twist disclination lines combined with edge dislocations, i.e., dispirations, are more preferable in the SmCA phase to a 2π twist disclination line as observed in the SmC phase.