Collective molecular motion during V-shaped switching in a smectic liquid crystal

The molecular motion during V-shaped switching in a homogeneously aligned smectic C*-like liquid crystal (LC) cell has been investigated by measuring the effective optical anisotropy Delta n(eff), apparent tilt angle theta(app), switching current: and second harmonic generation and comparing them with the simulated results based on mio extreme models, i.e., random model and collective model, where molecules switch randomly and collectively, respectively. The comparison revealed that the collective switching motion of LC molecules is more reasonable than the random motion. Moreover, it was also confirmed that the observed infrared absorption anisotropy of the phenyl stretching mode due to LC molecular distributions strongly supports the collective model. From these results, it was demonstrated that LC molecules do not switch randomly but all the LC molecules rotate collectively on a cone under the driving field.