SCIPRESS FORMA
Forma, Vol. 8 (No. 1), pp. 83-97, 1993
Review

Liquid Crystals and Topological Defects

Tetsuji Tokihiro

Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan

(Received April 30, 1993; Accepted June 4, 1993)

Keywords: Liquid Crystal, Topological Defects, Quasicrystal, TGB Phase

Abstract. We review the twist grain boundary phase (TGB phase) in liquid crystals which is a liquid crystal analogue of the Abrikosov flux phase in type II superconductors. It exhibits a two-dimensional quasicrystalline structure with crystallographically forbidden rotational symmetry due to the regular array of line dislocations. The theoretical model of this phase which is described as the system of polymers dissolved in chiral nematics are investigated in detail.