Dislocations and metastable chevrons in the electroconvective inplane normal roll state of a bent core nematic liquid crystal

作者：Krishnamurthy Kanakapura S^*; Tadapatri Pramod; Viswanath P

来源：Soft Matter, 2014, 10(37): 7316-7327.

DOI：10.1039/c4sm00906a

We report experimental results on the formation, dynamics, and annihilation of edge dislocations of opposite topological charge in the electroconvective inplane vortex state of a bent core nematic liquid crystal. The approach of paired, oppositely charged defects toward each other is a two-step process. Near constant velocity at large separation and accelerated motion close to annihilation are found, as in the case of nematic rolls belonging to standard electroconvection. Periodic arrays of dislocations of alternating polarity form upon a sudden, strong elevation of the control parameter. Chevron structures that appear between undulatory defect chains are metastable, and their decay with time is accompanied by an exponential reduction in the dislocation density. The initial periodicity of defect chains also drops exponentially with increasing field.

• 出版日期2014