Voltage-driven topological spin phase transitions in monolayer NiI₂

Electrical control of magnetism is a cornerstone for next-generation low-energy spintronics, yet realizing voltage-driven topological phase transitions in centrosymmetric lattices remains a significant challenge. Here, we propose a bias-voltage manipulation strategy based on first-principles calculations, offering a direct and field-free approach to control topological spin textures. Taking monolayer NiI₂ as an example, we reveal that an applied voltage effectively tunes the Kitaev easy-plane anisotropy and the Heisenberg exchange frustration. This electrical modulation drives a reversible phase transition between skyrmion and labyrinthine states. By combining tight-binding model analysis with Monte Carlo simulations, we elucidate the distinct roles of spin frustration and bond-dependent anisotropic interactions in stabilizing these topological defects. These findings provide a new way to manipulate the topological spin phases through a nonvolatile approach.