Formation of a twisted synclinic structure by an antiferroelectric liquid crystal material with strong quadrupolar interlayer coupling

Following the work of Rudquist [J. Mater. Chem. 9, 1257 (1999)], the thresholdless mode exhibited by some devices filled with some antiferroelectric liquid crystal materials is widely accepted to be due to the formation of a twisted synclinic structure in the device. In this work, we consider under what circumstances this structure forms in preference to the expected anticlinic structure. We show that a strong polar interaction at the surfaces is a necessary but not sufficient condition, and that a strong quadrupolar component of the interlayer interaction is also required. Examination of the stability of the possible ground states reveals a simple explanation for the frequency and temperature dependent electro-optical properties that are observed experimentally, including priming.