LCMRC researchers have
found an extraordinary nematic liquid crystal
phase, a new entry in the most widely studied and widely applied class of
liquid crystals. In the whole history of
liquid crystals only four distinct nematic ground states have been found: the uniaxial, the biaxial, and,
for chiral molecules, the
helical nematic and blue
phases. The “heliconical” phase reported here
is a fundamentally new type of nematic state exhibiting the first layer-free liquid crystal
ordering with coherent structure on the nanoscale. Its
spontaneously chiral conical helix,
appearing as broken symmetry since the bent molecular dimers such as CB7CB are achiral, exhibits the amazingly short pitch of 8nm, making it
the liquid crystal coherent ordering that is closest in scale to the molecular
size, in this case 3nm. This discovery,
as a result, promises a unique opportunity to advance liquid crystal science at
the interface of molecular design and soft matter physics.
