Multiplicative Noise-Induced Electrohydrodynamic Pattern Formations by Controlling Electric Conductivity

Abstract

We report multiplicative noise impacts on electroconvections (ECs) in a nematic liquid crystal. By controlling the intensity and cutoff frequency of a superposed electric noise (on a sinusoidal field for ECs), we investigate the variation in the characteristics of ECs such as thresholds and pattern diagrams in high-conductivity cells (σ ∼ 10 −6 Ω −1 m −1), in comparison with that in usual conventional cells (σ ∼ 10 −8 − 10 −7 Ω −1 m −1). Unpredictable threshold behaviors, unknown pattern formations such as isotropic liquid bubbles and EC-sustained phases, and undesirable dielectric breakdown induced by thermal focusing are found in high-conductivity cells.