Threading the Needle: Generating Textures in Nematics
  The Hopf fibration is an example of a texture: a topologically stable, smooth, global configuration of a field. Here we demonstrate the controlled sculpting of the Hopf fibration in nematic liquid crystals through the control of point defects. We demonstrate how these are related to torons by use of a topological visualization technique derived from the Pontryagin-Thom construction. 
Bryan Gin-ge Chen, Paul J. Ackerman, Gareth P. Alexander, Randall D.   Kamien, Ivan I. Smalyukh
cond-mat.soft cond-mat.mtrl-sci math-ph math.MP