在单一弹性常数近似下,利用映射方法和拓扑流理论研究了液晶中向错线对自由能密度的影响.指出自由能密度可以分为两部分,一部分是通常的液晶指向矢场在向错线周围的畸变能密度;另一部分是向错线自身的自由能密度,当指向矢场的Jacobian行列式在指向矢场的奇点处不等于零时,它是集中在向错线上并以(1)/(2)kπ为单位拓扑量子化的,拓扑量子数由指向矢场在向错线处的Hopf指数和Brouwer度(即向错强度)决定.当Jacobian行列式等于零时,利用拓扑流分歧理论详细研究了在指向矢场的极限点和分岔点处向错线自身的自由能密度的产生、湮灭和分歧过程,最后得出,具有高的拓扑量子数的向错线是不稳定的,它将通过分歧过程演化到拓扑量子数比较低的状态.
参考文献
[1] | Kleman M. Points, Lines and Walls: in Liquid Crystals, Magnetic Systems and Various Disordered Media[M].New York:J.Wiley,1983. |
[2] | Mermin N D. The topological theory of defects in ordered media[J]. Rev. Mod. Phys., 1979, 51(3): 591-648. |
[3] | Friedel J .Dislocations[M].Oxford: Pergamon,1964. |
[4] | Nabarro F R N. Theory of Crystal Dislocations[M].London:Oxford University Press,1976. |
[5] | Lubensky T C. Soft condensed matter physics[J]. Solid State Commun., 1997,102(2-3): 187-197. |
[6] | Holz A. Topological properties of static and dynamic defect configuarations in ordered liquids[J]. Physica A, 1992, 182(1-2): 240-278. |
[7] | 刘虹. 扭曲相液晶由外场引起的形变[J]. 液晶与显示,2001,16(4):251-260. |
[8] | 邵喜斌, 黄锡珉. 有限元法求解液晶层中的指向矢分布[J]. 液晶与显示,2001,16(3):163-169. |
[9] | 李伯符. 液晶物理 --磁场对液晶的作用[J]. 液晶与显示,2001,16(1):59-76. |
[10] | 邓罗根,何坤娜,胡海云. 光场与掺杂向列相液晶薄膜相互作用的若干问题[J]. 液晶与显示,2003,18(2):84-88. |
[11] | Dennes P G . The Physics of Liquid Crystals[M].London:Oxford University Press,1974. |
[12] | Yang G H, Duan Y S. Topological quantization of magnetic monopoles and their bifurcation theory[J]. Int. J. Theor. Phys., 1998, 37(9): 2371-2382. |
[13] | Yang G H , Duan Y S. The origin and bifurcation of disclinations in the gauge field theory of disclination and disclination continuum[J]. Int. J. Eng. Sci., 1999, 37(8): 1037-1050. |
[14] | Duan Y S,Yang G H, Jing Y. The origin and bifurcation of space-time defects in the early university[J]. Gen. Rel. Grav., 1997, 29(6): 715-725. |
[15] | Yang G H, Zhang H,Duan Y S. Topological aspect and bifurcation of disclination linesin two-dimensional liquid crystals[J]. Commun. Theor. Phs., 2002, 37(5): 513-518. |
[16] | Duan Y S, Yang G H,Jiang Y. The quantization of the space-time defects in the early universe[J]. Helv. Phys. Acta .,1997, 70: 565-577. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%