中国物理B ›› 2008, Vol. 17 ›› Issue (7): 2600-2609.doi: 10.1088/1674-1056/17/7/043
• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇 下一篇
罗开富, 蒋秀丽, 杨玉良
Luo Kai-Fu(罗开富)†, Jiang Xiu-Li(蒋秀丽), and Yang Yu-Liang(杨玉良)
摘要: Under a simple shear flow and in a static external magnetic field, the production of defects in the director-aligning regime of nematic liquid crystals has been investigated in terms of the Leslie--Ericksen theory. The equation of motion of the nematic director, which conforms to the driven over-damped sine-Gordon equation, has a soliton solution of the amplitude $\pi$. We show that the stationary state with the director uniformly oriented at a Leslie angle is only a metastable state and the potential, which governs the motion of the director, has a number of stable stationary states. For a strong magnetic field, the higher energy barrier between the stable and unstable states leads the director to be locked along the magnetic field direction. However, at the appropriate shear rate and magnetic field the defects, which appear as a stable solitary solution, can be nucleated from a uniformly aligned nematic liquid crystal. We have calculated the stationary travelling velocity of the solitary waves and the distance between a pair of defects.
中图分类号: (Defects in liquid crystals)