Director around singular points

Fig. 3.5.11. Director field around singular points. Any pattern on the left may be combined with any one on the right to give the field around a possible point...

The director structures around singular points associated with S = h-1 and S = -1 are sketched in Figure 6.3. 

The director lines distributed around one of these point singularities form a pattern reminiscent of the radial electric field produced by a charged particle, whereas the other singular pattern recalls the electric field about the zero point, lying in the middle of a segment the extremities of which are occupied by two identical electric charges. These singular points are very common in nematics and cholesterics. The two con-... 

Figure 5.4. Blue phases are composed of regions with double twist three such regions, with a singularity that relieves frustration between them, are shown in the figure. Two cylinders with double twist match at the contact point if the director tilt at their surfaces is h/4 however, the region where all three cylinders meet is singular. In current models, such singularities form a network of disclination lines. The circle marks the core of the disclination the insert shows the director lines around the core.

Figure 3.20 Examples of flux lines which are tangential to the orientation of the director n around an axial line disclination located perpendicular to the page and passing through the point indicated by a black dot. Various cases of Rrank index n are given together with the associated solution B provided by equation (3.341). The strength of such disclinations is often defined by s = f. The bold lines represent the singular radial lines obtained from equation (3.347). The constant 0o has been set to zero except for the examples of Prank index n = 2.

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