Ferroelectric phases in a chiral bent-core smectic liquid crystal: Dielectric and optical second-harmonic generation measurements

We report unambiguous evidence for ferroelectricity in a chiral bent-core l iquid crystal. This evidence includes (i) a single current peak in the pola rization reversal current, (ii) a strong dielectric response that is suppre ssed by applying a bias electric field, and (iii) strong optical second-har monic generation in the absence of electric field even at normal incidence. We propose a phase structure that is anticlinic in tilt and ferroelectric in polar order, i.e., smectic-CAPF*.