Surface depinning of smectic-A edge dislocations - art. no. 031705

Using a Landau-de Gennes approach, we model the formation of an edge disloc ation in a smectic-A cell initially in the bookshelf structure. The driving force is the mismatch between the layer thickness in a bulk smectic-A liqu id crystal and that imposed by confining plates. The core structure of the dislocation is calculated taking into account spatial variations of the sme ctic translational order parameter. We numerically determine the critical c ondition for the surface-driven formation and depinning of the dislocation. By exploiting this phenomenon, we show how the value of the positional anc horing strength at the surface can be determined.