Metal-insulator transition in surface-doped VO₂ nanowires at liquid helium temperature

The metal-insulator transition (MIT) in VO₂ nanowire devices, driven by electric field-induced nonequilibrium effects, is observed at liquid helium temperature. This unusually low transition temperature is achieved by surface doping VO₂ nanowires with gold nanoparticles (NPs). The presence of gold NPs may promote percolative conduction pathways, enhance electronic inhomogeneity, or alter lattice–electron coupling. These effects collectively enable a smoother MIT at a lower electric field compared to pristine VO₂ nanowires. An empirical model is used to distinguish Joule heating from electric field contributions, confirming the dominance of nonequilibrium electric field effects. Repeated voltage sweeps further reveal hysteresis and current variations, providing insights into carrier dynamics and correlated electron behavior introduced by NP decoration. These findings advance understanding of the MIT mechanism in VO₂ and emphasize the role of surface modifications in tailoring phase transitions at cryogenic temperatures.