Effect of the electric conductivity on the drift velocity of the cholesteric fingers of the second type in confined geometry

We show that the drift velocity of the cholesteric fingers of the second sp ecies in ac electric field strongly depends on the conductivity of the liqu id crystal chosen and exponentially vanishes above a cutoff frequency we fo und to be equal (within a numerical factor close to 1) to the charge relaxa tion frequency of the sample. We further show that the drift velocity is pr oportional to the applied electric field, provided that the confinement rat io is kept constant. [S1063-651X(99)06409-0].