 
Summary: Dynamics of Fluctuations below a Stationary Bifurcation to Electroconvection
in the Planar Nematic Liquid Crystal N4
XinLiang Qiu and Guenter Ahlers
Department of Physics and iQUEST, University of California, Santa Barbara, California 93106, USA
(Received 21 September 2004; published 3 March 2005)
We fitted Ck; ; / expÿk; to timecorrelation functions Ck; ; of structure factors
Sk; t; of shadowgraph images of fluctuations below a supercritical bifurcation at V0 Vc to electro
convection of a planar nematic liquid crystal in the presence of a voltage V
2
p
V0 cos2ft [k
p; q is the wave vector and V2
0 =V2
c ÿ 1]. There were stationary oblique (normal) rolls at small
(large) f. Fits of a modified SwiftHohenberg form to k; gave fdependent critical behavior for the
minimum decay rates 0 and the correlation lengths p;q.
DOI: 10.1103/PhysRevLett.94.087802 PACS numbers: 05.70.Jk, 05.40.a, 45.70.Qj, 64.60.Fr
Critical opalescence is a familiar phenomenon that oc
curs, for instance, near liquidgas critical points and near
