Early time evolution of Freedericks patterns generated from states of electroconvection

Abstract

We report on the early time ordering in a nematic liquid crystal subjected to a sudden change in external ac electric field. We compare time evolution for two different initial states of electroconvection. Electroconvection is a highly driven state of a nematic liquid crystal involving convective motion of the fluid and periodic variations of the molecular alignment. By suddenly changing either the voltage or the frequency of the applied ac field, the system is brought to the same thermodynamic conditions. The time ordering of the system is characterized by the evolution of features of the power spectrum, including the average wavenumber, total power, and shape of the the power spectrum. The differences between the two classes of quenches are discussed, as well as the possibility of scaling behavior during this initial phase of domain growth.