Dynamics of cholesteric liquid crystals in the presence of random magnetic fields

Based on dynamic renormalization group techniques, this letter analyzes the effects of external stochastic perturbations on the dynamical properties of cholesteric liquid crystals, studied in the presence of a random magnetic field. Our analysis quantifies the nature of the temperature dependence of the dynamics; the results also highlight a hitherto unexplored regime in cholesteric liquid-crystal dynamics. We show that stochastic fluctuations drive the system to a second-ordered Kosterlitz-Thouless phase transition point, eventually leading to a Kardar-Parisi-Zhang (KPZ) universality class. The results go beyond quasi-first-order mean-field theories, and provide the first theoretical understanding of a KPZ phase in distorted nematic liquid-crystal dynamics. Copyright (C) EPLA, 2015