Barbero G, Evangelista L R, Lelidis I
Dipartimento di Fisica del Politecnico and INFM, Corso Duca degli Abruzzi 24, I-10129 Torino, Italy.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 May;67(5 Pt 1):051708. doi: 10.1103/PhysRevE.67.051708. Epub 2003 May 27.
The possibility of spontaneous periodic distortions, depending on the tilt angle in a nematic liquid crystal sample, is investigated by means of a general formulation of the stability problem. It is shown that due to the presence of a surfacelike term in the free-energy density, the uniform pattern can be destabilized, giving rise to a periodic distortion of the director. Our analysis establishes, in general terms, the conditions for the formation of stable periodic structures in nematic samples. In particular, we determine the wavelengths for which the periodic distortion exists by investigating its dependence on the tilt angle, characterizing the uniform pattern, and on the saddle-splay elastic constant. The effect considered in our paper is a finite size effect, related to the slab geometry of the nematic sample under consideration.
通过稳定性问题的一般公式研究了向列型液晶样品中自发周期性畸变的可能性，该可能性取决于倾斜角。结果表明，由于自由能密度中存在类似表面的项，均匀图案可能会失稳，从而导致指向矢的周期性畸变。我们的分析从一般意义上确定了向列型样品中形成稳定周期性结构的条件。特别是，我们通过研究周期性畸变对倾斜角、均匀图案特征以及鞍形展曲弹性常数的依赖性，确定了存在周期性畸变的波长。我们论文中考虑的效应是一种有限尺寸效应，与所考虑的向列型样品的平板几何形状有关。
