Strong correlations and disorder driven metal to insulator transition in high entropy (MoVNbW)S₂ monolayer

Combining quantum confinement and high entropy in the recently synthesized two-dimensional (2D) high entropy transition metal (TM) dichalcogenides offers a platform for unique and unexplored electronic properties. Using density functional theory and tight-binding Hamiltonians, we have explored the role of disorder and strong electronic correlations on the metal-to-insulator transitions of (MoVNbW)S₂ monolayer. Our GGA+U results identify that the 1H phase is a half-metal that undergoes a metal-to-insulator transition in the spin ( ↑ ) channel with a Mott gap of 0.18 eV. The strongly correlated V-3d states drive the metal-to-insulator transition by suppressing the long-range TM−TM hopping. In addition, the 1H phase exhibits strong short-range ferromagnetism via the superexchange interactions of TM−V pairs, with localized magnetic moments on V atoms in the range of 1.3 ∼ 1.6µ_B. In contrast, geometric distortion in the 1T phase drives the metal-to-insulator transition by altering the charge density, opening a band gap of 0.37 eV. The 1T phase exhibits localized magnetic moments on V atoms (1.7 ∼ 1.9µ_B), with superexchange interactions occurring only between V−V pairs. Our findings contribute to understanding the complex interplay between disorder and strong electronic correlations in 2D high entropy TM dichalcogenides and provide a pathway for tailoring the electronic and magnetic properties of 2D high entropy materials.