1.Project title:

Patterns and Chaos in Electroconvection of Liquid Crystals

2. Principal Investigators:

a) Project Co-Director from a NATO country: Prof. Lorenz Kramer, Physikalisches Institut, Universität Bayreuth D-95440 email:lorenz.kramer@uni-bayreuth.de

b) Project Co-Director from a CP country: Prof. Agnes Buka, Research Institute for Solid State Physics and Optics of the Hungarian Academy of Sciences, e-mail:ab@szfki.hu

c) Other Principal Investigator: Prof. Guenter Ahlers, Department of Physics, University of California, Santa Barbara, CA 93106, USA, email:guenter@stc.ucsb.edu

3. Project Keywords: Pattern formation, spatio-temporal chaos, localized states, unconventional symmetry breacking, electroconvection, liquid crystals, unconventional materials

4. Research Plan:

We propose a collaborative research program aimed at the study of pattern forming instabilities in a class of nonlinear, nonequilibrium dissipative systems, with an emphasis on spatio-temporal chaos, localized "pulses", and other unconventional phenomena. We wish to deal with electically driven convection (EC) in nematic liquid crystals (NLC), which has in particular become a paradigm for anisotropic pattern formation. In addition to the opportunity to study generally important phenomena these systems give the possibility to extract information about an interesting class of materials. In fact, we intend to emphasize the study of "non-standard" NLCs which offer the chance to discover new phenomena. One of these is the NLC I52 where both spatio-temporal chaos and localized states ("worms") occur. Another is the material 10E6, where the conventional theoretical approach to EC appears to fail. Finally we propose to study not only the more usual planarly aligned layers where the nematic director is aligned parallel to the bounding plates, but also the rarer homeotropically aligned case, which belongs to a different symmetry class so that new effects occur. Patterns in spatially-extended dissipative systems have long intriqued scientist from a number of disciplines because their formation is generally associated with nonlineareffects which lead to qualitatively new phenomena that do not occur in linear systems.

2006. 02. 21