The unstable states of an antiferroelectric liquid crystal cell have been i
nvestigated, mapping out the unstable branch of the hysteresis loop. It was
found that the unstable branch extended over a much greater voltage range
than the quasistatic hysteresis loop of the cell. The narrow hysteresis loo
p is attributed to the influence of defects within the cell, which can seed
switching in the presence of a small energy barrier between initial and fi
nal states. The measurements indicate that the ferroelectric state may be f
undamentally stable at 0 V. (C) 2000 American Institute of Physics. [S0021-
8979(00)01011-2].