Landau theory of twist-induced biaxiality in cholesteric liquid crystals

The Landau theory of twist-induced biaxiality in cholesteric liquid crystals is presented. Results are given for the asymmetry parameter ηC as a function of temperature and chirality. These are compared with the experimental data of Yaniv et al. and the Maier-Saupe-type calculation of Lin-Liu and Lee. While the theoretical curves are qualitatively similar to those reported experimentally, the magnitude of the latter is as much as an order-of-magnitude greater than the theoretical prediction. Some possible reasons for this discrepancy are discussed.