SURFACE-DEFECTS AND FORCES IN NEMATIC LIQUID-CRYSTAL SAMPLES

The existence of surface defects resulting from the inhomogeneity of t he surface treatment in a nematic liquid crystal sample of definite th ickness is investigated. We consider two significant experimental arra ngements for the flat surfaces, in the hypothesis of strong anchoring. By means of a theoretical model, the force between the surface defect s is analytically determined. The forces are shown to have a nonlinear dependence on the relative displacement between the defects.