External Noise Effect on the Onset of Williams Domain in Nematic Liquid Crystals

Abstract

In order to examine the effect of external noise on the electrohydrodynamic instability, we have measured the wave number spectrum of the pattern of Williams domain in nematic liquid crystals MBBA in the presence of external noise superposed to the ac voltage. The threshold voltage for the onset of Williams domain is found to shift to higher values with increasing noise power. Its noise dependence is interpreted in terms of a theory presented by Dubois-Violette et al.