Chiral symmetry-breaking dynamics in the phase transformation of nematic droplets

Chiral symmetry-breaking equilibrium textures in deformable and nondeformable droplets of achiral nematic liquid crystals (LCs) have long been observed for a broad range of LC compounds and conditions. Most of the observed chiral symmetry-breaking phenomena in achiral nematic LCs have involved spherical nematic droplets, which serve as ideal geometries for studying the interaction between surface and bulk elastic effects on nematic texture.

In this work, continuum simulations are performed of the formation of an initially isotropic phase nematic LC confined within a nanoscale nondeformable droplet with weak homeotropic surface anchoring conditions. Simulation conditions are chosen for the case where the equilibrium nematic texture is uniform. Beginning with an initial quench of the isotropic phase droplet, nematic formation occurs, initially forming an unstable radial-like texture. Subsequently, a spontaneous symmetry-breaking twist-mediated defect escape mechanism is observed for material parameters corresponding to pentyl-cyanobiphenyl (5CB) prior to the droplet evolving to stable uniform texture. Notably, this dynamic mechanism does not occur in simulations using the single-constant elastic constant approximation.