Eur. Phys. J. E 1, 179-188
Interface dynamics in liquid crystals
C. Chevallard - M. Clerc - P. Coullet - J.-M. Gilli
Institut Non-Linéaire de Nice, 1361 route des
Lucioles, 06560 Valbonne, France
clerc@inln.cnrs.fr
Received 5 August 1999 and Received in final form 13 September 1999
Abstract
We have experimentally observed the pattern instabilities of an Ising wall
formed in a nematic or cholesteric liquid crystal layer. We have deduced an envelope
equation, relevant close to the Fréedericksz transition,
from which we derived an equation for the dynamics of the interface
in the vicinity of its bifurcation. In the case of the zig-zag instability, this model is
characterized by a conservative and variational order parameter whose gradient satisfies
a Cahn-Hilliard equation. We have also investigated the influence of slightly broken
symmetries on the dynamical behaviour of the system. The disappearance of the interface
translational invariance or of the reflection symmetry along the wall axis may induce new
interfacial patterns which have been both experimentally and theoretically pointed out.
PACS
47.20.Ma Interfacial instability -
47.20.Ky Nonlinearity (including bifurcation theory) -
61.30.Gd Orientational order of liquid crystals; electric and magnetic field effects on
order
Copyright EDP Sciences, Società Italiana di Fisica, Springer-Verlag
