Fission of quasi-static dissipative solitons in chiral nematics

Dissipative solitons in liquid crystals (LCs) are represented by three-dimensional solitary waves of director deformation called directrons. The only one exception on the quasi-static counterparts of directrons has ever been observed in achiral nematics. In this work, quasi-static solitons and their fission are identified in chiral nematics. The structure, distribution and fission of quasi-static solitons are closely related to the pitch of samples. The critical pitch is about 7.0 µm for LC cells with thickness of ∼10.0 µm. Quasi-static solitons are transformed from directrons by stepping down voltage to facilitate locating solitons. Successive two-soliton fission with increasing fission time occurs for all quasi-static solitons in samples of relatively larger pitches. Multi-soliton fission is also found in some quasi-static solitons when the voltage is stepped up back to the directron domain, leaving behind a region that can modify the trajectories of surrounding directrons. The fission of quasi-static solitons in chiral nematics has predictable fission location, adjustable fission time, and controllable fission number, may acting as an excellent model system for studying general principles of soliton fission in nonlinear systems.