Related Experiment Video
Updated: Aug 28, 2025

10:35
Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
Published on: May 29, 2018
8.8K
Defect absorption and emission for p-atic liquid crystals on cones
Farzan Vafa1, Grace H Zhang2, David R Nelson2
1Center of Mathematical Sciences and Applications, Harvard University, Cambridge, Massachusetts 02138, USA.
Physical Review. E
|September 16, 2022
Summary
We studied 2D liquid crystals on curved surfaces, finding their ground states depend on geometry. Cone apexes exhibit effective charges, influencing defect behavior and leading to absorption or emission.
Area of Science:
- Soft Matter Physics
- Materials Science
- Geometry and Topology
Background:
- Understanding the behavior of liquid crystals on curved surfaces is crucial for advanced materials and devices.
- The influence of intrinsic geometry on the elastic and topological properties of two-dimensional (2D) liquid crystals is not fully understood.
Purpose of the Study:
- To investigate the ground-state configurations of 2D liquid crystals with p-fold rotational symmetry (p-atics) on fixed curved surfaces.
- To analyze the role of intrinsic geometry, specifically focusing on cones, in determining defect behavior and stability.
Main Methods:
- Utilized isothermal coordinates to simplify the elastic potential by explicitly encoding geometric contributions.
- Developed an analytical framework to describe the effective topological charge of cone apexes and their interaction with topological defects.
- Performed numerical simulations to validate analytical predictions for defect configurations on cones with varying angles.
Main Results:
- Identified an effective topological charge at the cone apex, dependent on the cone's deficit angle, which dictates defect absorption and emission.
- For a disk, ground states feature p defects of charge +1/p arranged in a ring.
- On cones, three distinct ground-state configurations emerge based on the cone angle: complete defect absorption at the apex, partial absorption with ring formation, or all defects forming a ring on the flank.
Conclusions:
- The intrinsic geometry of curved surfaces significantly dictates the ground-state configurations and defect dynamics of 2D liquid crystals.
- Cone apexes act as tunable elements for defect management, enabling absorption or emission based on geometric parameters.
- The findings provide a comprehensive analytical and numerical understanding of topological defect behavior in curved liquid crystal systems.

