Dynamics of a polar electro-optic effect in surface states in nematic liquid crystals

We have studied the dynamic properties of a polar electro-optic effect in two surface states in a planar nematic liquid crystal. This polar effect arises from an external symmetry breaking of anisotropic interfacial interactions created by two different aligning layers. The necessary symmetry-breaking is at least comparable to the weak anchorage and the associated relaxation is on the scale of a few hundred microseconds. The relaxation time decreases effectively as the square of the applied field but its asymmetry is a linear function of the field as well as the difference in the surface energies. Some aspects of the dc bias effect is also discussed for practical applications.