Molecular dynamics simulations of surface-induced ordering in a nematic liquid crystal

By means of a molecular dynamics simulation, we show that a uniaxial nematic liquid crystal may exhibit an unusual ordering that appears within a few molecular lengths from a rough surface. In contact with the surface, a smectic-C layering is induced. Moving towards the bulk, the smectic order disappears and a decrease of the uniaxial orientational order below the bulk value occurs. The intermediate region between the surface-induced smectic-C ordering and the bulk nematic is characterized by a considerable degree of biaxiality. Correspondingly, the director orientation undergoes a strong distortion close to the surface.