STABILITY AND METASTABILITY IN NEMATIC GLASSES: A COMPUTATIONAL STUDY

摘要

The influence of randomly distributed impurities on liquid crystal (LC) orientational ordering is studied using a simple Lebwohl-Lasher type lattice model in two (d=2) and three (d=3) dimensions. The impurities of concentration p impose a random anisotropy field-type of disorder of strength w to the LC nematic phase. Orientational correlations can be well presented by a single coherence length ξ for a weak enough w. We show that the Imry-Ma scaling prediction w ξ∝ w~(-2/(4-d)) holds true if the LC configuration is initially quenched from the isotropic phase. For other initial configurations the scaling is in general not obeyed.