Twist instability of a flexoelectric nematic domain in an external field.

Abstract

We report the observation of an instability in a flexoelectric nematic domain due to a linear coupling with an external dc electric field. We use a hybrid aligned nematic cell with two antiparallel flexopolarized domains. Above a certain threshold, the field induces a twist instability in domains with the flexopolarization opposed to the field. The threshold field in methoxybenzylidenebutylaniline is in reasonable agreement with a calculation which also includes the effect of the dielectric anisotropy.