Defects dynamics in roll structures of twisted nematics

V. Delev1, E. Batyrshin, O. Scaldin1*, Y. Lebedev1§, Y. Timirov1
1Institute of Physics of Molecules and Crystals RAS, prospect Oktaybray 151, 450075 Ufa
Abstract
Dynamics of singular and nonsingular defects in the periodic structures of rolls arising at electroconvection in nematic liquid crystals twisted by π/2 has been studied. The emergence of non-singular defects is associated with an axial component of the velocity of the hydrodynamic flows whose direction is opposite in the neighboring rolls. At some voltage U>Uc both these struc-tural defects starts to oscillate. It is shown that the average frequency of the "zig-zag" oscillation decreases with increasing size of the defects.
Received: 10 March 2015   Revised: 05 May 2015   Accepted: 10 June 2015
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