Nematic point defect annihilation in a cylindrical capillary

Abstract

We perform a numerical study of the annihilation of nematic radial and hyperbolic point defect. Both the pre-collision and post-collision stages are taken into account. Initially a pair of defects is induced at the axis of the cylindrical capillary. A semi-microscopic interaction potential and the Brownian molecular dynamics are used. In the early stage the cores of defects are negligibly mutually influenced. Their relative velocity is inversely proportional to the separation d between defects. As d becomes comparable to the nematic correlation length, the cores significantly deform. During the collision the defects merge and become indistinguishable. In the post-collision regime the order parameter at the collision site gradually recovers the equilibrium configuration.