Contribution of dechiralization lines to electro-optical response and dielectric permittivity in the SmC* phase

In the ferroelectric SmC* phase of antiferroelectric liquid crystal in planar geometry, a new contribution to the electro-optical and dielectric responses was found. This mode which we propose to be called a "surface layer mode", appears with the apparition of 2 pi-disclinations (dechiralization lines) in the texture. Some evidences of the existence of this mode are given. A simple model, taking into account a transformation of a pair of pi-disclination on the surface to one 2 pi-disclination in the bulk is discussed.