Soft-mode turbulence in electrohydrodynamic convection of a homeotropically aligned nematic layer

Abstract

The experimental study of electroconvection in a homeotropically aligned nematic (MBBA) is reported. The system undergoes a supercritical bifurcation “rest state-spatiotemporal chaos.” The chaos is caused by long-wavelength modulation of the orientation of convective rolls. For the first time the observations both below and beyond the Lifshitz point are accompanied by quantitative analysis of temporal autocorrelation functions of turbulent modes. The dependence of the correlation time on the control parameter is obtained. A secondary bifurcation from normal to abnormal rolls is discussed. © 1997 The American Physical Society.