Electric field induced generation and dynamics of defects in drops of nematic cholesterics

The electric field induced dynamics and interconversion of defects in nematic cholesteric drops has been studied experimentally. It has been demonstrated that, depending on the applied voltage and the ratio of the drop radius to the equilibrium helix pitch, $R/P$, orientational structural interconversions of different types can be realized. In particular, when the condition $R/P\le$ 1 is satisfied, drops with defects of only one type, namely, the Frank–Price defect, which rotates upon application of an alternating electric voltage, are observed. In the case of $R/P\ge$ 1, the rotational dynamics of the defect is transformed during its disintegration into two surface defects with the force $m$ = 1.