title: Topological polymer dispersed liquid crystals with bulk nematic defect lines pinned to handlebody surfaces.
abstract: Polymer dispersed liquid crystals are a useful model system for studying the relationship between surface topology and defect structures. They are comprised of a polymer matrix with suspended spherical nematic drops and are topologically constrained to host defects of an elementary hedgehog charge per droplet, such as bulk or surface point defects or closed disclination loops. We control the genus of the closed surfaces confining such micrometer-sized nematic drops with tangential boundary conditions for molecular alignment imposed by the polymer matrix, allowing us to avoid defects or, on the contrary, to generate them in a controlled way. We show, both experimentally and through numerical modeling, that topological constraints in nematic microdrops can be satisfied by hosting topologically stable half-integer bulk defect lines anchored to opposite sides of handlebody surfaces. This enriches the interplay of topologies of closed surfaces and fields with nonpolar symmetry, yielding new unexpected configurations that cannot be realized in vector fields, having potential implications for topologically similar defects in cosmology and other fields.
authors.affiliation: Department of Physics, University of Colorado, Boulder, Colorado 80309, USA and Liquid Crystal Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Campbell
authors.affiliation: Max-Planck-Institut für Intelligente Systeme, Heisenbergstraße 3, D-70569 Stuttgart, Germany and Institut für Theoretische Physik IV, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany.
authors.forename: Mykola
authors.initials: M
authors.lastname: Tasinkevych
authors.affiliation: Department of Physics, University of Colorado, Boulder, Colorado 80309, USA 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