Structure and dynamics of the Frenkel-Kontorova dislocations in electroconvection in liquid crystals
- Russian Academy of Sciences, Institute of Molecular and Crystal Physics, Ufa Scientific Center (Russian Federation)
The Frenkel-Kontorova instability is studied in a 1D lattice of domains formed during electroconvection in nematic liquid crystals twisted by {pi}/2. It is found that generation of defects by such instability can be observed in this model medium. Among other things, it is shown that several types of defects with singular and nonsingular cores, as well as with a extended core, are formed in the 1D domain structure above the electroconvective instability threshold. The extended cores of dislocations are dissociated into a line, and the entire structure is isomorphic to two partial dislocations spaced by a certain distance, which are not observed in free form. Defects with a nonsingular core (zero topological index) exist owing to spiral hydrodynamic flows in convective rolls and are not observed in layers with a homogeneous orientation of molecules. It is shown that the formation of both types of defects follows the scenario of decay of dislocations with extended cores via detachment of nonsingular defects (i.e., discretely); as a result, a dislocation with a singular core is left. 'Breather' defects, which are the result of periodic creation and annihilation of dislocations with a topological index of {+-}1, are also observed. The effect of defects on the transition from the 1D to 2D structures is considered.
- OSTI ID:
- 21067584
- Journal Information:
- Journal of Experimental and Theoretical Physics, Vol. 103, Issue 6; Other Information: DOI: 10.1134/S1063776106120107; Copyright (c) 2006 Nauka/Interperiodica; Article Copyright (c) 2006 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
- Country of Publication:
- United States
- Language:
- English
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