Geometric transformation and three-dimensional hopping of Hopf solitons

Hopf solitons are three-dimensional particle-like field distortions with nontrivial topology. Tai et al. show stable Hopf solitons in a liquid crystal material in the absence of an electric field or geometric confinement, their transformation and hopping-like dynamics in response to electric pulses. Arising in many branches of physics, Hopf solitons are three-dimensional particle-like field distortions with nontrivial topology described by the Hopf map. Despite their recent discovery in colloids and liquid crystals, the requirement of applied fields or confinement for stability impedes their utility in technological applications. Here we demonstrate stable Hopf solitons in a liquid crystal material without these requirements as a result of enhanced stability by tuning anisotropy of parameters that describe energetic costs of different gradient components in the molecular alignment field. Nevertheless, electric fields allow for inter-transformation of Hopf solitons between different geometric embodiments, as well as for their three-dimensional hopping-like dynamics in response to electric pulses. Numerical modelling reproduces both the equilibrium structure and topology-preserving out-of-equilibrium evolution of the soliton during switching and motions. Our findings may enable myriads of solitonic condensed matter phases and active matter systems, as well as their technological applications.

Automated summary

Researchers have discovered stable Hopf solitons in a liquid crystal material, which are particle-like field distortions with nontrivial topology in three dimensions. By tuning the energetic costs of different gradient components in the molecular alignment field, the stability of Hopf solitons is enhanced. Electric fields allow for the inter-transformation of Hopf solitons between different geometric embodiments and their three-dimensional hopping-like dynamics in response to electric pulses.