Liquid Crystal Films with Defects

Abstract

We investigate the structure of nematic and smectic C liquid crystal thin films whose textures include topologically induced defects. In the case of a chiral smectic C film the defects interact with the film’s spontaneous polarization causing thickened islands to form. Using Landau models we characterize the number, location, and degree of the induced defects. Smectic C films have tilted molecules and have a vector description. In this case we prove that minimal energy states have defects with degree 1. Tangential nematic fields are characterized by tensor fields and we prove that minimizing states for these have defects of degree .