Observation of Backflow during the Anihilation of Topologocal Defects in Freely Suspended Smectic Films

Freely suspended films in the smectic C phase are excellent templates for study of topological defect dynamics. It is well known that, during annihilation a pair disclinations with strengths +/?1, +1 moves faster because it carried towards its opponent by backflow, whereas flow vicinity ?1 negligibly small. This backflow pattern created motion itself. An experimental confirmation this theoretical prediction and quantitative characterization achieved here fluorescence labeling. Film regions near positions labeled their displacements tracked optically.