Generation of the Planar Solitons Using Thermal Trapping of a Disclination in Nematic Liquid Crystals and Their Applications

摘要

The mesophase properties of nematic liquid crystals render them ideal forcontrolling and studying topological defects. The planar soliton, a π-wall inthe form of a string with a constant thickness shown in a nematic, is a topologicaldefect lacking singularity. Herein, a thermal laser tweezer is introducedto trap the disclination at the isotropic–nematic interface induced by thethermal effect and to move the trapped disclination under the low anchoringcondition, which enables to generate solitons as if they were drawn and tocontrol them actively. The soliton, which is created or annihilated in accordancewith topological charge conservation, exhibits cosmic string intercommutation.Thus, the dynamics of cosmic strings can be implemented by usingsolitons in a nematic. To demonstrate potential applications of the solitons,microsized cargo delivery and polarization diffraction gratings are presented,which could be used in lab-on-a-chip and implemented in various photonicapplications, respectively, and prove the applicability of a topological defectthrough complete control.