Strain engineering magnetocrystalline anisotropy in strongly correlated VTe2 with room-temperature ferromagnetism

Abstract

Two-dimensional (2D) magnetic transition metal dichalcogenides have attracted great interest in various fields, including information storage, logic devices, and high-frequency detectors. However, the currently reported 2D magnets are limited by their low Curie temperatures. Based on the density-functional theory calculation, we predicted the metastable $H$ phase $\mathrm{V}{\mathrm{Te}}_{2}\phantom{\rule{4pt}{0ex}}(\mathrm{H}\text{\ensuremath{-}}\mathrm{V}{\mathrm{Te}}_{2})$ is a promising room-temperature 2D in-plane ferromagnetic semiconductor without charge-density wave (CDW) transition. To achieve the $H\text{\ensuremath{-}}\mathrm{V}{\mathrm{Te}}_{2}$ from the $T$ phase or CDW-phase $\mathrm{V}{\mathrm{Te}}_{2}$, electron doping is proposed as a feasible strategy in practice. Moreover, the significant modulation effect of external strain fields on the magnetocrystalline anisotropy energy and magnetic ordering of monolayer $H\text{\ensuremath{-}}\mathrm{V}{\mathrm{Te}}_{2}$ are systematically studied. The electron correlation included from a $\mathrm{Hubbard}\text{\ensuremath{-}}U$ term has a profound influence on the ground state of magnetic order of $H\text{\ensuremath{-}}\mathrm{V}{\mathrm{Te}}_{2}$, as well as the direction of the easy-magnetization axis. These results not only provide an in-depth understanding of the modulation mechanism of the magnetic $H\text{\ensuremath{-}}\mathrm{V}{\mathrm{Te}}_{2}$, but also shed light on the potential applications of $H\text{\ensuremath{-}}\mathrm{V}{\mathrm{Te}}_{2}$ in spintronics and sensors.