title: Topological defects in cholesteric liquid crystal shells.
abstract: We investigate experimentally and numerically the defect configurations emerging when a cholesteric liquid crystal is confined to a spherical shell. We uncover a rich scenario of defect configurations, some of them non-existent in nematic shells, where new types of defects are stabilized by the helical ordering of the liquid crystal. In contrast to nematic shells, here defects are not simple singular points or lines, but have a large structured core. Specifically, we observe five different types of cholesteric shells. We study the statistical distribution of the different types of shells as a function of the two relevant geometrical dimensionless parameters of the system. By playing with these parameters, we are able to induce transitions between different types of shells. These transitions involve interesting topological transformations in which the defects recombine to form new structures. Surprisingly, the defects do not approach each other by taking the shorter distance route (geodesic), but by following intricate paths.
authors: EC2M, UMR 7083 Gulliver, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France. Teresa.Lopez-Leon@espci.fr.
authors: Alexandre
authors: A
authors: Darmon
authors: EC2M, UMR 7083 Gulliver, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France. Teresa.Lopez-Leon@espci.fr.
authors: Michael
authors: M
authors: Benzaquen
authors: Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia.
authors: Simon
authors: S
authors: Čopar
authors: EC2M, UMR 7083 Gulliver, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France. Teresa.Lopez-Leon@espci.fr.
authors: Olivier
authors: O
authors: Dauchot
authors: EC2M, UMR 7083 Gulliver, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France. Teresa.Lopez-Leon@espci.fr.
authors: Teresa
authors: T
authors: Lopez-Leon