Field-induced peculiarities in the dynamics of the director reorientation in confined nematic liquid crystals

Abstract

The peculiarities in the dynamics of the director reorientation in confined nematic liquid crystals (LCs) under the influence of a strong electric field E directed at an angle α to the magnetic field B have been investigated theoretically on the basis of the hydrodynamic theory including the director motion with appropriate boundary and initial conditions. Analysis of the numerical results for the turn-on process, when the strong electric field E is suddenly applied, provides an evidence for the appearance of the spatially periodic patterns in confined LC film. Calculations show that when the angle α tends to be 90°, the optimum wavelength, giving the fastest response, provides the lower effective viscosity γeffα, which is less than one in the bulk nematic phase. So, a lower value of γeffα gives a faster relaxation times, as observed experimentally by using the time-resolved deuterium NMR spectroscopy.