title: Self-assembly of skyrmion-dressed chiral nematic colloids with tangential anchoring.
abstract: We describe dipolar nematic colloids comprising mutually bound solid microspheres, three-dimensional skyrmions, and point defects in a molecular alignment field of chiral nematic liquid crystals. Nonlinear optical imaging and numerical modeling based on minimization of Landau-de Gennes free energy reveal that the particle-induced skyrmions resemble torons and hopfions, while matching surface boundary conditions at the interfaces of liquid crystal and colloidal spheres. Laser tweezers and videomicroscopy reveal that the skyrmion-colloidal hybrids exhibit purely repulsive elastic pair interactions in the case of parallel dipoles and an unexpected reversal of interaction forces from repulsive to attractive as the center-to-center distance decreases for antiparallel dipoles. The ensuing elastic self-assembly gives rise to colloidal chains of antiparallel dipoles with particles entangled by skyrmions.
authors.affiliation: Department of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA and Department of Physics, VSSD College, Kanpur 208 002, India.
authors.forename: M B
authors.initials: MB
authors.lastname: Pandey
authors.affiliation: Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia.
authors.forename: T
authors.initials: T
authors.lastname: Porenta
authors.affiliation: Department of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: J
authors.initials: J
authors.lastname: Brewer
authors.affiliation: Department of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: A
authors.initials: A
authors.lastname: Burkart
authors.affiliation: Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia and Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
authors.forename: S
authors.initials: S
authors.lastname: Copar
authors.affiliation: Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia and Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
authors.forename: S
authors.initials: S
authors.lastname: Zumer
authors.affiliation: Department of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA and Department of Electrical, Computer, and Energy Engineering and Materials Science and Engineering Program, University of Colorado, Boulder, Colorado 80309, USA and Renewable and Sustainable Energy Institute, National Renewable Energy Laboratory and University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Ivan I
authors.initials: II
authors.lastname: Smalyukh
mesh_terms: D016880:Anisotropy; D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D004548:Elasticity; D021621:Imaging, Three-Dimensional; D018715:Microscopy, Video; D008956:Models, Chemical; D017711:Nonlinear Dynamics; D061848:Optical Imaging; D052898:Optical Tweezers
chemical_list: D003102:Colloids