Abstract
The electrohydrodynamic instability in a homeotropically oriented nematic system occurs after the Freedericksz transition which leads to the Goldstone mode due to additional symmetry. In the system with no magnetic field the transition from a rest state to spatiotemporal chaos via the supercritical bifurcation, that is, soft-mode turbulence occurs. In the presence of magnetic fields the bifurcation point to spatiotemporal chaos shifts to higher value of control parameter with intensity magnetic fields. Above convection thresholds, normal rolls (the wavevector of the pattern k is parallel to the C-director) appear at the frequency of the applied AC-voltage beyond the Lifshitz point (LP), and oblique rolls below LP.
