Electric-field effects in the twist-bend nematic phase

摘要

In the recently discovered Twist-Bend Nematic (N_(TB)) phase, the nematic director is spontaneously distorted and twisted along a conical helix with an extremely short pitch, ～10 nm. We have investigated the behavior of the N_(Tb) phase subject to an electric-field. We show that, due to the periodic N_(TB) structure, the electro-optic effects are not nematic-like but are close analogs to those in the smectic and cholesteric phases. In particular, we have studied the fast (sub-microsecond) flexoelectrically-induced rotation of the optic axis, which is similar to the electroclinic effect in the SmA~* phase and the flexoelectric response of short-pitch cholesterics. We discuss the possible applications of the fast N_(TB) electro-optic effects.