Stable Assemblies of Topological Defects in Nematic Orientational Order

Area of Science:

• Condensed Matter Physics
• Soft Matter Physics
• Theoretical Physics

Background:

• Topological defects (TDs) are fundamental in physical fields, but their assemblies are energetically unfavorable.
• Thermotropic nematic liquid crystals (NLCs) offer an accessible platform for studying universal behaviors of TDs.
• TDs in NLCs have potential applications, motivating research into their stabilization.

Purpose of the Study:

• To investigate general mechanisms for stabilizing localized assemblies of topological defects (TDs).
• To explore the role of curvature in the phase component of order parameter fields for TD stabilization.
• To demonstrate how NLCs can serve as a model system for understanding TD behavior.

Main Methods:

• Utilizing a Landau-type approach to model the nematic tensor order parameter in NLCs.
• Analyzing the impact of chirality and saddle splay elasticity on TD stabilization.
• Investigating the influence of Gaussian curvature on TD assembly in 2D curved manifolds.

Main Results:

• The coupling between chirality and Gaussian curvature can stabilize Meron TDs in NLCs.
• Gaussian curvature significantly influences the assembly and stabilization of TDs in curved systems.
• Strong curvature can act as an attractor for TDs, potentially stabilized by impurities during phase transitions.

Conclusions:

• Curvature, particularly Gaussian curvature, is a key factor in stabilizing topological defects.
• Meron TDs, stabilized by curvature, have broad relevance across different physics domains.
• Nematic liquid crystals provide an excellent system for experimental studies of topological defect physics.