Abstract

Macroscopic systems can exhibit disordered patterns, such as fingerprints, vegetation patterns, and dendrites, which have topological defects that characterize the pattern richness, but their self -organization is unknown. Here, we investigate the formation mechanisms, defect emergence, and topological transition between disordered patterns driven by the heating rate. Based on a thermally driven chiral nematic liquid crystal experiment, we identified the coexistence of two different types of patterns at the same temperature but different heating rates. A supercritical transition is revealed by measuring the density of pattern defects. The pairwise correlation length also suggests this transition. Theoretically, we account for this transition based on an amplitude equation with a chiral term that is valid close to the winding/unwinding transition. Likewise, a prototype model of pattern formation exhibits a similar transition, showing that the transition is universal and could be observed in magnetic, optical, fluid, chemical, and ecological systems.