Gate-Tunable Correlated Electronic State in Atomically Thin Single-Crystal VO _2−δ

The realization of high-quality two-dimensional (2D) correlated oxides remains a long-standing challenge, particularly for nonlayered systems where structural instability and stoichiometric sensitivity hinder atomic-scale synthesis. Here, we report the chemical vapor deposition (CVD) growth of atomically thin, single-crystalline bronze-phase vanadium dioxide (2D VO_2-δ), achieved through a hydrogen-confined, self-terminating process. The resulting 2D crystals exhibit monolayer-level thickness precision and lateral sizes up to hundreds of micrometers, offering an unprecedented material platform for exploring correlation-driven physics. By electrostatic ionic gating, we induce a hole-doped correlated metallic state that is absent in the bulk counterpart, unveiling transport signatures consistent with strong electron correlations. These findings demonstrate the promise of 2D transition metal oxides (TMOs) as a platform for studying high-temperature-correlated quantum phenomena and for the development of quantum electronic devices working at room temperature.