Hexagonal transition metal dichalcogenides (TMDCs) represent a famous material family with rich structural phases and elemental compositions, whose diverse electronic properties, like magnetism, topological property, and superconductivity (SC), spark promising applications in the interdisciplinary field of “XX-tronics”. Here we found tetragonal TMDCs with distorted Lieb ($d\mathrm{Lieb}$) lattice present similar electronic properties as hexagonal TMDCs, by demonstrating the stability of transition metal diselenides ($d\mathrm{Lieb}-M{\mathrm{Se}}_2$) and ditellurides ($d\mathrm{Lieb}-M{\mathrm{Te}}_2$) with semiconductivity, half-metallicity, magnetic metallicity, topological electronic states, or phonon-mediated SC. Specifically, $d\mathrm{Lieb}-\mathrm{TiS}{\mathrm{e}}_2$ and $d\mathrm{Lieb}-\mathrm{TiT}{\mathrm{e}}_2$ are semiconductors, whereas partial occupation of localized $d_{z^2}$ states induces Stoner magnetism in $d\mathrm{Lieb}-M{\mathrm{Se}}_2$ ($M=\mathrm{Nb}$, V, Cr) with half-metallicity and in $d\mathrm{Lieb}-\mathrm{MnS}{\mathrm{e}}_2$ with metallicity. Notably, as the only TMDC monolayer with the magnetism stemming from Nb atom, $d\mathrm{Lieb}-\mathrm{NbS}{\mathrm{e}}_2$ monolayer was found exhibiting exotic chiral topological edge states. The Stoner magnetism will be suppressed in $d\mathrm{Lieb}-\mathrm{FeS}{\mathrm{e}}_2$ monolayer with fully occupied $d_{z^2}$ states, which could enable phonon-mediated SC with a transition temperature $T_{\mathrm{C}}\sim 4$ Kelvin. Together with our previously proposed disulfides $d\mathrm{Lieb}-M{\mathrm{S}}_2$, this work provides an overview table for tetragonal TMDCs with diverse electronic properties, which appear as promising alternatives for hexagonal TMDCs in the application of “XX-tronics”.

Close

PrevNext

View figure in article

• Electronic structure
• Ferromagnetism
• First-principles calculations
• Superconductors
• Transition metal dichalcogenides