Entangled nematic disclinations using multi-particle collision dynamics

TL;DR

This paper introduces a mesoscale simulation method to study the complex dynamics and topological transitions of colloidal disclinations in nematic liquid crystals, revealing metastable states and the effects of hydrodynamic fluctuations.

Contribution

It develops a novel numerical approach combining nematohydrodynamics and topological defect analysis to model colloid interactions and defect dynamics in out-of-equilibrium conditions.

Findings

Reproduces far-field colloid interactions

Resolves topological properties of disclination loops

Identifies metastable defect states and transitions

Abstract

Colloids dispersed in nematic liquid crystals form topological composites in which colloid-associated defects mediate interactions while adhering to fundamental topological constraints. Better realising the promise of such materials requires numerical methods that model nematic inclusions in dynamic and complex scenarios. We employ a mesoscale approach for simulating colloids as mobile surfaces embedded in a fluctuating nematohydrodynamic medium to study the kinetics of colloidal entanglement. In addition to reproducing far-field interactions, topological properties of disclination loops are resolved to reveal their metastable states and topological transitions during relaxation towards ground state. The intrinsic hydrodynamic fluctuations distinguish formerly unexplored far-from-equilibrium disclination states, including configurations with localised positive winding profiles. The adaptability and precision of this numerical approach offers promising avenues for studying the dynamics of colloids and topological defects in designed and out-of-equilibrium situations.