Spin polarization driven by a charge-density wave in monolayer $1T{\textbackslash}text{-}\{{\textbackslash}mathrm\{{TaS}}}_{2}$

Abstract

Using first-principles calculations, we investigate the electronic and vibrational properties of monolayer [Math Processing Error]-phase [Math Processing Error]. We demonstrate that a charge-density wave is energetically favorable at low temperature, similar to bulk [Math Processing Error]. Electron-phonon coupling is found to be essential for the lattice reconstruction. The charge-density wave results in a strong localization of the electronic states near the Fermi level and consequently in spin polarization, transforming the material into a magnetic semiconductor with enhanced electronic correlations. The combination of inherent spin polarization with a semiconducting nature distinguishes the monolayer fundamentally from the bulk compound as well as from other two-dimensional transition metal dichalcogenides. Monolayer [Math Processing Error]-phase [Math Processing Error] therefore has the potential to enable two-dimensional spintronics.