Smectic Layer Rotation in Antiferroelectric Liquid Crystal

Smectic layer rotation in the antiferroelectric liquid crystal upon application of asymmetric pulses of electric field has been observed. Application of the electric field with sawtooth waveform of more than 103 cycles induces rotation of the direction of the smectic layer normal by more than 60° away from the initial alignment axis even in the sample without surface treatment for a unidirectional alignment. This rotation is reversible, and the layer rotates in the opposite direction upon application of pulses of electric field with opposite polarity. This anomalous layer rotation has been tentatively interpreted to originate from the essential difference in F →AF and AF →F transition mechanisms.