Liquid crystal defect structures with Mobius strip topology

Topological solitons commonly appear as energy-minimizing field configurations, but examples of stable, spatially localized objects with coexisting solitonic structures and singular defects are rare. Here we use a nonpolar chiral liquid crystal system to show how twist domain walls can co-self-assemble with vortices to form spatially localized topological objects with spontaneous folding. These soliton-vortex assemblies, which we call 'mobiusons', have a topology of the molecular alignment field resembling that of the Mobius strip's surface and package localized field excitations into folded structures within a confinement-frustrated uniform far-field background. Upon supplying energy in the form of electric pulses, mobiusons with different overall symmetries of structure exhibit folding-dependent rotational and translational motions, as well as topological cargo-carrying abilities that can be controlled by tuning the amplitude and frequency of the applied fields. We demonstrate on-demand transformations between various mobiusons and show examples of encoding information by manipulating folds in such structures. A model based on the energetics of solitons and vortices provides insights into the origins of the folding instability, whereas minimization of the Landau-de Gennes free energy closely reproduces details of their internal structure. Our findings may provide a route towards topology-enabled light-steering designs.

Automated summary

We demonstrate the co-self-assembly of twist domain walls and vortices to form localized topological objects called 'mobiusons' in a nonpolar chiral liquid crystal system. These mobiusons exhibit folding-dependent rotational and translational motions, as well as controlled topological cargo-carrying abilities. Our findings may contribute to the development of topology-enabled light-steering designs.