Geometry and mechanics of disclination lines in 3D nematic liquid crystals. Issue 8 (20th January 2021)

• Record Type: Journal Article
• Authors: Long, Cheng; Tang, Xingzhou; Selinger, Robin L. B.; Selinger, Jonathan V.
• Is Part Of: Soft matter. Volume 17:Issue 8(2021)
• Page Start: 2265
• Page End: 2278
• Publication Date: 2021-01-20
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/d0sm01899f
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : In nematic liquid crystals, disclination lines have several geometric features, which can be characterized by vectors and tensors. Based on these features, the mechanical forces on disclination lines can be calculated. Abstract : In 3D nematic liquid crystals, disclination lines have a range of geometric structures. Locally, they may resemble +1/2 or −1/2 defects in 2D nematic phases, or they may have 3D twist. Here, we analyze the structure in terms of the director deformation modes around the disclination, as well as the nematic order tensor inside the disclination core. Based on this analysis, we construct a vector to represent the orientation of the disclination, as well as tensors to represent higher-order structure. We apply this method to simulations of a 3D disclination arch, and determine how the structure changes along the contour length. We then use this geometric analysis to investigate three types of forces acting on a disclination: Peach–Koehler forces due to external stress, interaction forces between disclination lines, and active forces. These results apply to the motion of disclination lines in both conventional and active liquid crystals.