On-Off Intermittency in Stochastically Driven Electrohydrodynamic Convection in Nematics

Abstract

We report on-off intermittency in electroconvection of nematic liquid crystals driven by a dichotomous stochastic electric voltage. With increasing voltage amplitude we observe laminar phases of undistorted director state interrupted by shorter bursts of spatially regular stripes. Near a critical value of the amplitude the distribution of the duration of laminar phases is governed over several decades by a power law with exponent $\ensuremath{-}3/2$. The experimental findings agree with simulations of the linearized electrohydrodynamic equations near the sample stability threshold.