Reorientational dynamics of conjugated nematic point defects

Abstract

To appreciate the universal qualitative features of defect annihilation in nematic liquid crystals, we study how the viscous force of reorientational dynamics behaves under a transformation that reverses the sign of the defect's topological charge. As an illustration of our general results, we consider a class of point defects that were first studied by A. Saupe. The reorientational viscous forces acting on them differ dramatically from those acting on line defects

The Symmetries of Octupolar Tensors

“…However, as shown in [14], in 3D A cannot in general be represented in terms of a single vector as in (2.11) and (2.10) becomes a more versatile tool to describe the directions along which the integral lines of n are fluted around a point defect. In particular, it might be interesting to compute A in (2.10) for the combed defects described in [38] and their distortions possibly due to the interaction with other point defects nearby (see also [39]). The complete classification of the symmetries enjoyed by A, which we give in this paper, may supplement the topological classification of defects by providing extra synthetic information on the qualitative features of the director field surrounding the defect.…”

Backflow-mediated domain switching in nematic liquid crystals

“…This was then cleanly demonstrated by a joint experimental and theoretical study in a quasi-2D geometry [25]. The pair-annihilation asymmetry of various types of nematic defects was addressed subsequently [26][27][28].…”

“…The competing numerical methods used to approach the hydrodynamic part of the problems have been mainly the discretization of the generalized continuum Navier-Stokes equation [ [22,[32][33][34][35][36]. Alternative methods include smoothed particle hydrodynamics, radial basis function collocation methods, and other hybrid or semianalytic approaches [26,[37][38][39][40].…”

Topological defects of nematic liquid crystals confined in porous networks

“…Hyperbolic and radial point defects in nematics are topologically equivalent (they can be transformed continuously into one another); therefore, assigning a positive or negative topological charge to them is arbitrary. 18,19 Nevertheless, it is very common to assign a positive charge +1 to a radial point defect and a negative charge À1 to a hyperbolic hedgehog, 5,20 according to the so-called winding number. The reason is that a radial point defect and a hyperbolic defect, when brought together, annihilate and give a defect-free state.…”