ELASTIC DISTORTIONS OF COMPRESSIBLE SMC

In this paper, the elastic distortions of compressible smectics are investigated near the boundary of a pair of opposite chevron layer structures on the basis of the elastic theory. The Lagrange multipliers are explicitly taken into account to assure the orthogonality of the wave vector a and the c-director as well as the normalization of c. In addition an external DC electric field effect is also investigated. From numerical computations, it is concluded that there exists a parallelogram region with a flat layer and a uniform c-director configuration between the two opposite chevrons. In addition the external electric field is found to break up the symmetry of the layer structure and result in the layer undulation along the electric field.