POSSIBILITY OF TWIST-GRAIN-BOUNDARY STRUCTURE IN NONCHRIAL LIQUID-CRYSTALS

Recent studies of highly chiral liquid crystals suggest that twist in smectic phases can be supported by the introduction of periodic twist grain boundaries that would produce a helical structure formed by smectic blocks that are twisted with respect to each other. Here, we examine the possibility of observing such a structure in nonchiral smectic liquid crystals. Experimental results suggest that such structures may be obtained by confining ordinary nonchiral liquid crystals in a cell in which the directors at the two surfaces are nonparallel.