GEOMETRICAL ANCHORING AT AN INCLINED SURFACE OF A LIQUID-CRYSTAL

The free energy of a nematic film, placed between two isotropic media, does not depend on the azimuthal angle if the two interfaces are parallel. It is shown that in the general case of nonparallel bounding, a particular value of the azimuthal orientation is energetically preferable. The directions of this geometrically imposed easy axis and of the thickness gradient need not necessarily coincide. The geometrical anchoring may induce the twist deformations and force the nematic liquid crystal to behave like an optically active object.