Influence of surface tension on the stability of edge dislocations in smectic A liquid crystals

Abstract

The general solution describing an edge dislocation inside a smectic A film is presented. Its elastic interaction energy with the limiting surfaces is calculated by taking into account rigorously the surface tension γ. This formula is used to discuss the dislocation stability with respect to a slip motion towards the surface. If surface tension prevails over smectic A elasticity, characterized by elastic constants K and B, i.e. if γ> (KB)1/2, then the dislocation is stabilized within the film. If, by contrast, the surface tension is small (γ< (KB)1/2), the dislocation is attracted to the surface of the film.