Nematic ordering and defects on the surface of a sphere: A Monte Carlo simulation study

We examine the ordering of hard rods on the surface of a sphere using computer simulations. As predicted by previous theories of thin nematic shells we observe four s=+1/2 defects. However, the predicted tetrahedral symmetry for the defects and the baseball director configuration is not observed. Instead the four defects are located, on average, on a great circle which splits the sphere into two hemispheres, each of which has a splay dominated director configuration. We argue that this result occurs as the bend elastic constant for hard rods is much larger than the splay elastic constant. (c) 2008 American Institute of Physics.