Noise-induced threshold shift and pattern formation in electroconvection by controlling characteristic time scales
Noise-induced threshold shift and pattern formation in electroconvection by controlling characteristic time scales
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DOI：
10.1103/physreve.84.025302
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发表时间：
2011-08-26
影响因子：
2.4
通讯作者：
Huh, Jong-Hoon
中科院分区：
文献类型：
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作者：
Huh, Jong-Hoon
我们报告了外部噪声引起的阈值漂移和图案形成的交流驱动的电对流（EC）在液晶。我们研究了噪声强度对阈值的依赖性，并确定了噪声的特征截止频率（f*（c））与EC的特征交流频率（f（cd））之间的关系f*（c）= hf（cd）（a）（α近似为1.4，h近似为0.1）。对于f（c）> f*（c），噪声有助于稳定EC（即，向上阈值偏移），而对于f（c）向下阈值偏移）。对于f（c）= f*（c），噪声对阈值偏移没有贡献。然而，EC的特征波长强烈地依赖于噪声强度，而不是f（c）。
We report external noise-induced threshold shift and pattern formation in ac-driven electroconvection (EC) in nematic liquid crystals. We investigate the noise intensity dependence of the threshold and determine the relationship f*(c) = hf(cd)(a) (alpha similar to 1.4, h similar to 0.1) between the characteristic cutoff frequency (f*(c)) of the noise and the characteristic ac frequency (f(cd)) of EC. For f(c) > f*(c), the noise contributes to stabilizing EC (i.e., upward threshold shift), whereas for f(c) < f*(c), it contributes to destabilizing EC (i.e., downward threshold shift). For f(c) = f*(c), the noise makes no contribution to the threshold shift. However, the characteristic wavelength of EC strongly depends on the noise intensity but not on f(c).