Curvature induced quasi-melting from rough surfaces in nematic liquid crystals

The Berreman-de Gennes model, describing the azimutal anchoring energy of a nematic material oriented by a grooved surface, is revisited. When the groove wave-length is shorter than the nematic-isotropic coherence lenght, the nematic should decrease locally its order parameter to decrease the too large curvature energy induced by the boundaries. This curvature induced surface quasi-melting could explain recent observations on the order parameter decrease close to oblique SiO evaporated rough surfaces.