Nonthermal current-induced transition from skyrmion lattice to nontopological magnetic phase in spatially confined MnSi

An electronic/magnetic order often turns into a different phase of matter when the temperature, pressure, or magnetic field varies, and resulting changes in physical quantities form the basis of various switching devices. By contrast, global phase changes triggered by electric current with minimal Joule heating often remain elusive, although it may offer exotic possibilities for phase manipulation in micro/nanoscale materials. Here, we report the experimental and numerical realizations of a nonthermal current-induced magnetic transition for a spatially confined skyrmion-hosting system. In a microfabricated MnSi, the application of a DC current triggers a nonvolatile suppression of the topological Hall effect, comparable in magnitude to that observed for the skyrmion-to-nonskyrmion thermodynamic transition of the whole system. A similar current-induced global transition is also found in numerical simulations with open boundaries. These phenomena are not seen either in the corresponding bulk system or in the simulation with periodic boundaries, thus, indicating a key role of the confined geometry in the nonthermodynamic phase change triggered by current.