First Order Phase Transition Accompanying Soliton Lattices near a Tricritical Point –Chiral Smectic C Liquid Crystal in an Electlic Field–

Static sine-Gordon system with misfit is analyzed near a tricritical point found by Schaub and Mukamel. At that point, a bifurcation of a uniform state to a twin of soliton lattice branches is found to occur in a similar way as the case of ordinary first order transition, that is, an instability type of phase transition named by de Gennes. Behaviours of the soliton lattices, such as their profiles and free energies and so on, are studied in detail and compared with those of this ordinary first order transition. An instability of soliton lattices reported before has turned out to be connected with the existence of another type of soliton lattice found newly. A correspondence of a linear analysis on a soliton tail with the theory by Schaub and Mukamel is indicated.