Origin of the differing pre-polarity-reversal current peak in polar smectic phases

Determine why the pre-polarity-reversal current peak associated with molecular tilt is generally larger and broader in heliconical polar SmC phase (SmCₚᴴ) materials than in the non-helical polar SmC phase (SmCₚ).

Background

The paper compares the non-helical polar SmCₚ phase observed in 5-Me 2 with heliconical polar SmCₚᴴ phases reported in related materials. Current-response measurements show a small peak before polarity reversal, which the authors associate with the reformation of molecular tilt. Although a corresponding peak is also present in heliconical SmCₚᴴ materials, its magnitude and breadth are typically greater than in the non-helical SmCₚ phase. The authors explicitly state that the reason for this difference remains unresolved, making its physical origin an open problem in understanding the coupling between molecular tilt, polarisation reversal, and helical order in polar smectic liquid crystals.