Relaxation kinetics of stretched disclination lines in a nematic liquid crystal

The dynamics of disclination defect lines in a nematic liquid crystal are measured experimentally and considered theoretically. An optical trap is used to deform the line, enabling the previously unexplored regime of large deformation to be accessed. The relaxation follows a linear decay at large amplitude, crossing over into the well understood exponential decay at small amplitude. Both regimes can be described by simple theoretical arguments. The crossover point is well described by the theory, but the experiments show a faster than expected dynamics, indicating that the effective viscosity in the models is overestimated.