Electrohydrodynamic instabilities in nematic liquid crystals driven by a dichotomous stochastic voltage

Noise Effects on Threshold of Electrohydrodynamic Convection in Nematic Liquid Crystals

“…13) In theoretical studies, on the other hand, the observed linear relation was successfully explained, although the physical approaches used were quite different. [7][8][9][10]20) Moreover, the relation was also reported in other systems such as a magnetic (or electric) field-induced Freedericksz transition, which deals with a spatially homogeneous instability in order to avoid the wave number dependence of the noise. 1,21) Recently, Behn et al have successfully reproduced the wave number dependence of the noise in their stochastic stability model.…”

“…Up to now, several groups have extensively investigated the threshold shift for the onset of electroconvection by considering the intensity and correlation time of the noise. [7][8][9][10][11][12][13]20) Previous experimental results are as follows: (i) The superposition of the stochastic noise (V N ) increases the deterministic threshold voltage (V c ) for WDs. This means that the noise plays a role in stabilizing the initially stationary state of the system.…”

Response of electrohydrodynamic convection to external noise

“…As a result, the threshold Vc for WDs increases with increasing noise intensity VN (i,e" b > 0). Such stabilization effect of noise was well understood in earlier theories [4][5][6][7][8] and experiments [4][5][6]9]. However, sufficiently colored noise (fc < fc * ) having a long correlation time TN can accumulate more space charge for EHC by aiding the ac field.…”

“…(or correlation time TN) [4][5][6][7][8][9]. By considering an expanded CH mechanism in external multiplicative noise [5,7,8] stabilization effects due to the noise-driven random oscillation against the periodic ac-based CH instability. Recently, we noticed that if fc becomes lower than the critical value fc ., the noise plays a role in destabilization, which facilitates the CH instability.…”

“…Stochastic resonance [3], multiplicative stochastic processes [4], and noise-induced pattern formations [2] are well-known nontrivial noise phenomena. In this study, we address noise-induced threshold shifts and pattern change in ac-driven electrohydrodynamic convections (EHC) in nematic liquid crystals (NLCs) [4][5][6][7][8][9].…”