Entangled nematic disclinations using multi-particle collision dynamics

Area of Science:

• Soft Matter Physics
• Materials Science
• Computational Physics

Background:

• Colloids in nematic liquid crystals form topological composites with defect-mediated interactions.
• Existing numerical methods struggle with dynamic and complex scenarios involving these materials.
• Understanding colloidal entanglement kinetics is crucial for realizing the potential of these composites.

Purpose of the Study:

• To develop and employ a mesoscale simulation approach for modeling mobile colloids in liquid crystals.
• To investigate the kinetics of colloidal entanglement and the behavior of associated topological defects.
• To explore far-from-equilibrium configurations and topological transitions of disclination loops.

Main Methods:

• Simulated colloids as mobile surfaces within a fluctuating nematohydrodynamic medium.
• Utilized a mesoscale approach to capture both far-field interactions and defect dynamics.
• Resolved topological properties of disclination loops during relaxation processes.

Main Results:

• Successfully reproduced far-field interactions between colloids.
• Identified metastable states and topological transitions of disclination loops.
• Revealed novel far-from-equilibrium disclination states, including those with localized positive winding profiles, driven by hydrodynamic fluctuations.

Conclusions:

• The developed mesoscale simulation approach accurately models colloidal entanglement in liquid crystals.
• This method provides insights into the dynamics of topological defects, including previously unexplored states.
• The approach is adaptable for studying designed and out-of-equilibrium systems involving colloids and defects.