Chiral induction in nematics A computer simulation study

Abstract

We have studied chiral induction in a nematic in contact with a chiral surface using computer simulations. Nematic and surface particles have been modelled using the Gay–Berne (GB) potential considering, additionally, a short-range chiral term for the inducing surface. We find that, close to the chiral surface, a twist of the local director with respect to the surface molecules is induced, even in the isotropic phase. In the nematic phase, the twist is maintained through orientational correlation and, even well inside, the sample molecules are effectively twisted with respect to the surface director. This process can highlight the basic mechanism of the chiral induction of a cholesteric, i.e. chiral nematic, phase. A detailed description of the molecular organization at various distances from the inducing surface is presented, using scalar and pseudoscalar orientational correlation functions.