Study of Layer Relaxations of Chevrons in SmC* Phase

In this paper, based on a continuum theory of compressible smectics, we shall analyze a layer relaxation phenomenon between a couple of antiparallel chevrons. From the two-dimensional analyses of the layer structure and the c-director configuration, we have found that there exist two kinds of layer relaxations depending on the boundary conditions, i.e., dilative or compressive mode. It is found that such symmetry breaking between the compressive geometry and the dilative one is considered to result from symmetry of the elastic free energy concerned with layer compression. A layer undulation is found to occur in the dilative mode, but not in the compressive one. This finding seems to correspond to the buckling instability which has been experimentally observed in the smectic phase under layer dilation.