Liquid Crystal Ground States on Hyperbolic Cones

Abstract

We generalize the analytic theory and simulation models for liquid crystal ground states on conventional cones with positive apex Gaussian curvature and study liquid crystal ground states on hyperbolic cones with a delta function of negative apex Gaussian curvature. While both the local apex curvature on a conventional cone and a hyperbolic cone lead to a fixed unquantized pseudodefect in the conformal domain and behave like conventional disclinations with opposite topological charges, there are fundamental differences in the ground states as well, which can be viewed as a violation of charge conjugation symmetry in a liquid crystal phase. To illustrate the violated charge conjugation symmetry on curved surfaces, we study two simple examples: (a) $p$-atic liquid crystals on a hyperbolic cone with free boundary conditions at the cone base. (b) $p$-atic liquid crystals on a hyperbolic cone with tangential boundary conditions at the cone base. In the simple case of $p=1$ liquid crystals (a vector order parameter field) on a hyperbolic cone with tangential boundary conditions, the positive pseudocharge caused by the apex curvature can be stably bound with a topological charge of the same sign despite their repulsive interaction, in sharp contrast to the charge conjugated situation associated with conventional cones.