Defect trajectories in nematic shells: Role of elastic anisotropy and thickness heterogeneity

David Sec (1) , Teresa Lopez-Leon (2) , Maurizio Nobili (2) , Christophe Blanc (2) , Alberto Fernandez-Nieves (3) , Miha Ravnik (4) , Slobodan Zumer (1)

1 Department of Physics [Ljubljana]
2 Matière Molle
3 Georgia Institute of Technology [Atlanta]
4 Rudolf Peierls Centre for Theoretical Physics

We introduce the idea of transformation trajectories to describe the evolution of nematic shells in terms of defect locations and director field when the elastic anisotropy and the shell thickness heterogeneity vary. Experiments are compared to numerical results to clarify the exact role played by these two parameters. We demonstrate that heterogeneity in thickness is a result of a symmetry breaking initiated by buoyancy and enhanced by liquid crystal elasticity, and is irrespective of the elastic anisotropy. In contrast, elastic anisotropy--in particular, disfavored bend distortion--drives an asymmetric defect reorganization. These shell states can be both stable or metastable.

Domaines: Matière Molle [cond-mat.soft]

David Sec, Teresa Lopez-Leon, Maurizio Nobili, Christophe Blanc, Alberto Fernandez-Nieves, et al.. Defect trajectories in nematic shells: Role of elastic anisotropy and thickness heterogeneity. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2012, 86, pp.020705. ⟨10.1103/PhysRevE.86.020705⟩. ⟨hal-00733363⟩