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Abstract
The soliton-concept seems to be a valuable tool in interpretation of various phenomena in chiral liquid crystalline systems. Two such phenomena are communicated: the cholesteric phase distorted by magnetic field, and the blue phases.
The de Gennes description of cholesteric phase distorted by magnetic field allows the soliton interpretation. The solitons are considered as concentrated turns of the cholesteric spiral, isolated by nematic-like regions. The deuterium NMR spectra calculated using this soliton concept are in excellent agreement with the measured spectra.
The soliton concept offers an elegant solution of the mystery of the blue phases. These phases are explained here as soliton crystals. Solitons in the blue phases are suggested to be spherical creatures. Their presence is the consequence of the break-down of the nematic ordering below the cholesteric-isotropic transition temperature. The lack of the nematic ordering destabilizes the cholesteric pitches allowing them to have a soliton form representing a small coherence length and rapid inner molecular dynamics. These spherical solitons are able to form the different crystal lattices already observed. The blue fog phase might be a concentrated soliton gas or liquid. Most of the experimental results can be succesfully explained on this basis.