SOLITARY WAVES IN AN ANTIFERROELECTRIC LIQUID-CRYSTAL

The antiferroelectric liquid crystalline phase and related ferrielectr ic phases exhibit a rich variety of physical behavior. Recently we hav e been examining the dynamics of these materials. For materials whose dielectric anisotropy Delta epsilon < 0, we find a critical threshold d.c. field E(th) in the Sm C-A phase, above which solitary waves prop agate rapidly along the layer direction. These solitary waves, which c onsist of ferroelectric regions propogating into an antiferroelectric sea, may be ''frozen'' in place by reducing the field to E(th), or for ced to retreat by reducing the field to E < E(th).