Pattern Formation in Homeotropically Oriented Nematics

Abstract

The experimental investigation of the bifurcation to spatiotemporal chaos is conducted in the electrohydrodynamic instability in homeotropically oriented nematic systems. The convective instability in the homeotropically oriented nematic system occurs via the Freedericksz transition showing the zero-wavenumber Goldstone mode due to additional symmetry such as continuous rotational one. It was found that the transition from a spatially uniform rest state to spatiotemporal chaos occurs via the supercritical bifurcation with the softening of the irregular motions toward the bifureation point. We name therefore this type of spatiotemporal chaos the soft mode turbulence. The obtained results are discussed with the model equation recently proposed.