Effects of external noise on the Fréedericksz transition in a nematic liquid crystal

We have determined the effects of imposing dichotomous noise on the magnetic Fréedericksz transition in the nematic liquid crystal MBBA. Various states of the nematic orientation occur, depending on the magnitude of the dc field and the amplitude and correlation time of the noise component. The resultant phase diagrams are in partial agreement with the analytic results of Horsthemke, Doering, Lefever, and Chi for H>${\mathit{H}}_{\mathit{c}}$. A substantial deviation of the experimental result from computer simulations based on their model for low magnetic field (H<${\mathit{H}}_{\mathit{c}}$) is observed.