Threshold Characteristics of Electrohydrodynamic Instability in Nematic Liquid Crystals under a Superimposing Magnetic Field

We reported about AC-driven electrohydrodynamic instability in nematic liquid crystals. The characteristics of the threshold field for instability were investigated in Hele-Shaw type cells. We found a remarkable threshold change in the presence of a superimposing magne tic field, which plays a role in suppressing instability. We discuss force competition between the electric field causing the instability and the magnetic field suppressing the instability. Compared to the top-view type cells, moreover, the characteristics of the instability found in the present Hele-Shaw (side-view) cells are discussed