Shear flow induced polarization in ferroelectric smectics C

The existence of ferroelectricity in the chiral smectic C phase has been established from polarization measurements in the presence of an electric field [1]. In this article we study the case where the polarization is created by applying a shear velocity parallel to the smectic planes : The helicoidal structure is distorted by the shear : The alignment effect induces the average dipoles in the smectic C planes to align perpendicular to the plane of the shear. The dynamics of the effect gives information on the elasticity and viscosity of the process. A significant increase of the polarization observed near the smectic A transition is discussed.