Modelling defect-bonded chains produced by colloidal particles in a cholesteric liquid crystal

Abstract

We use a Landau-de Gennes free-energy model to investigate interactions generated by spherical particles with strong planar anchoring immersed in a cholesteric liquid crystal. With a pitch of ∼1.5 times the particle diameter, the +1 boojums present for a particle in a nematic split into four +1/2 defects leading to defect lines in the bulk around the particle which look like handles emerging from its surface. When multiple particles are present, handles from adjacent particles join together, forming a defect bond between them. We present results for defect-bonded chains, and investigate the energies associated with this bonding.