Fractional topological solitons in nonlinear viscoelastic ribbons with tunable speed

A unique type of domain-wall solitons, fractional topological solitons, have been recently theoretically shown to arise in minimal surface ribbons and demonstrate topological robustness. Here we study these fractional topological solitons experimentally using 3D printed helicoid ribbons and computationally using finite-element analysis (FEA). We show that these fractional solitons propagate at constant speed despite the strong dissipation in the viscoelastic material the ribbon consists of, and this speed can be sensitively controlled by an axial load. The nonlinear viscoelastic FEA quantitatively captures fine features of this fractional soliton. The results verify the predicted fractional solitons, and more importantly, open a new pathway of realizing and controlling topological fractional excitations in systems with complex material features including nonlinearity and viscoelasticity.