Nucleation and growth of cholesteric fingers under electric field

Abstract

We have studied the behavior of a cholesteric liquid crystal sandwiched between two plates, with homeotropic anchoring, in the presence of an electric field. By changing two control parameters, namely the sample thickness and the electric field magnitude, we were able to characterize different types of solutions: a nematic phase (unwound cholesteric), isolated doubly twisted fingers, a periodic pattern of fingers arranged side by side, and a transient singly twisted translationally invariant configuration. Including the electric field contribution to the calculations of reference [3], we have computed a theoretical phase diagram that agrees well with the experimental data. The consideration of anisotropic elasticity in our calculations was essential in explaining our observations