Annihilation trajectory of defects in smectic-C films

TL;DR

This paper investigates how elastic anisotropy influences the trajectories of annihilating defects in smectic-C films, extending existing theories to better match experimental observations of defect behavior.

Contribution

The study introduces elastic anisotropy into defect trajectory models, providing a more accurate theoretical framework for understanding defect annihilation in smectic-C films.

Findings

Elastic anisotropy significantly alters defect trajectories.

Extended theory better matches experimental defect paths.

Curved trajectories depend on elastic properties.

Abstract

In a 2D liquid crystal, each topological defect has a topological charge and a characteristic orientation, and hence can be regarded as an oriented particle. Theories predict that the trajectories of annihilating defects depend on their relative orientation. Recently, these predictions have been tested in experiments on smectic-C films. Those experiments find curved trajectories that are similar to the predictions, but the detailed relationship between the defect orientations and the far-field director is different. To understand this difference, we extend the previous theories by adding the effects of elastic anisotropy, and find that it significantly changes the curved trajectories.