Theoretical investigation of antiferroelectric (SmCA⁎) subphases by hydrodynamical approach

We provide a hydrodynamical approach utilizing time dependent Landau-Ginzburg model (L-G) and the Cahn-Hilliard model (C-H) to investigate antiferroelectric liquid crystals (AFLCs) exhibiting different chiral phases between paraelectric smectic A (SmA⁎) phase and antiferroelectric smectic CA⁎ phase (SmCA⁎). Introducing conserved and non-conserved order parameters in C-H and L-G models, we have predicted the appearance of a chiral smectic C (SmC⁎) phase and a ferrielectric SmCFI1⁎ phase (three layers SmCA⁎) in an antiferroelectric phase sequence. The three layers periodicity for SmCFI1⁎ phase is studied in detail with a non-uniform layer interactions among smectic layers with strong experimental support. Finally, we provide some theoretical basis for the non-uniformity of our proposed layer interactions.