Eur. Phys. J. E 4, 389-396

Director configuration and dynamics of a nematic liquid crystal around a two-dimensional spherical particle: Numerical analysis using adaptive grids

J. Fukuda¹ and H. Yokoyama<sup>1, 2

1</sup>  Yokoyama Nano-structured Liquid Crystal Project, ERATO, Japan Science and Technology Corporation, 5-9-9 Tokodai, Tsukuba 300-2635, Japan
²  Molecular Physics Section, Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba 305-8568, Japan

fukuda@nanolc.jst.go.jp

(Received 14 September 2000 and Received in final form 27 December 2000)

Abstract
We study numerically the director and orientational order parameter configurations in a nematic liquid crystal around a two-dimensional spherical particle on the basis of the tensor order parameter formalism. To properly account for the large length scale difference between the particle and the accompanying orientational defect, we devise an adaptive grid scheme in which the lattice spacing is automatically and locally adjusted in response to the spatial gradient of the orientational order parameter. This adaptive grid scheme is useful in studying dynamical as well as static orientational structures. We present a simulation result which shows how a hedgehog defect of topological charge -1 becomes unstable in two dimensions, and splits into a defect pair of topological charge -1/2, located symmetrically around the particle.

PACS
61.30.Cz - Theory and models of liquid crystal structure.
61.30.Jf - Defects in liquid crystals.


© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001