V型液晶分子系统的蒙特卡罗模拟

Monte Carlo Simulations of Liquid Crystals Formed by V-Shaped Molecules

摘要: 本文采用蒙特卡罗方法研究电偶极矩对V型液晶分子系统相变行为的影响。计算结果表明，随着分子电偶极矩强度的增加，系统的朗道点，即各向同性相到双轴向列相的相变不仅仅发生在当分子夹角为正四面体角()时，而是出现了一系列的朗道点，换句话说，朗道点变成了一条朗道线。此外，双轴向列相的范围明显扩大，从而大大提高双轴向列相出现的概率。

Abstract: Monte Carlo simulations have been performed to study the phase diagram of liquid crystals formed by V-shaped molecules with an electric dipole moment. Simulation results show that as the electric dipole moment in-creases, the Landau point where phase transits directly from the isotropic to the biaxial nematic occurs not only when the bend angle is at the tetrahedral angle () but also at other bend angles. In other words, the Landau point be-comes a Landau line. Besides, the range of the biaxial nematic phase has been immensely expanded, indicating a more stable biaxial nematic phase.