  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 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 provides the first
theoretical understanding of a KPZ phase in distorted nematic liquid crystal
dynamics.
