Chiral nematic liquid crystals in cylinders: Layering transition and conservation of layer structure

Chiral nematic lyotropic chromonic liquid crystals (LCLCs) confined in a cylindrical cavity exhibit layering transition and intriguing topological defects. With a planar degenerate anchoring at the cavity wall, the chiral LCLCs have the double-twist (DT) director configuration. To our interest, as we increase the chiral dopant concentration, the degree of twist in the DT configuration increases discontinuously. This "step-like" layering transition occurs because there exist local minima in the elastic free energy landscape; depending on the dopant concentration, one of the minima becomes the ground state. Consequently, meta-stable domains with different twist angles can coexist with dislocation-like defects between them. Lastly, we learn that the meta-stable domains are topologically protected because of the layer number conservation.