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

Abstract 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)S 2 monolayer. Our GGA+ U results identify that the 1H phase is a half-metal that undergoes a metal-to-insulator transition in the spin ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo stretchy="false">↑</mml:mo> </mml:mrow> </mml:math> ) channel with a Mott gap of 0.18 eV. The strongly correlated V-3 d 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 ∼ 1.6 µ 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 ∼ 1.9 µ 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.