Light-matter interaction induces a single positive vortex with swirling arms

Abstract

Homeotropic nematic liquid crystal cells with a photosensitive wall and negative dielectric anisotropy exhibit, under the influence of local illumination, stable vortexes with swirling arms that are trapped at the illuminated area. Close to the Fréedericksz transition an amplitude equation is derived, which allows us to understand the origin of the induced vortex and the competition between the illuminating profile and the elastic anisotropy generating the swirling of the arms.