Prediction of superconductivity in a series of tetragonal transition metal dichalcogenides.

Transition metal dichalcogenides (TMDCs) represent a well-known material family with diverse structural phases and rich electronic properties; they are thus an ideal platform for studying the emergence and exotic phenomenon of superconductivity (SC). Herein, we propose the existence of tetragonal TMDCs with a distorted Lieb (Lieb) lattice structure and the stabilized transition metal disulfides (MS), including Lieb-ZrS, Lieb-NbS, Lieb-MnS, Lieb-FeS, Lieb-ReS, and Lieb-OsS. Except for semiconducting Lieb-ZrS and magnetic Lieb-MnS, the rest of metallic Lieb-MS was found to exhibit intrinsic SC with the transition temperature () ranging from ∼5.4 to ∼13.0 K. The of Lieb-ReS and Lieb-OsS exceeded 10 K and was higher than that of the intrinsic SC in the known metallic TMDCs, which is attributed to the significant phonon-softening enhanced electron-phonon coupling strength. Different from the Ising spin-orbit coupling (SOC) effect in existing non-centrosymmetric TMDCs, the non-magnetic Lieb-MS monolayers exhibit the Dresselhaus SOC effect, which is featured by in-plane spin orientations and will give rise to the topological SC under proper conditions. In addition to enriching the structural phases of TMDCs, our work predicts a series of SC candidates with high intrinsic and topological non-triviality used for fault-tolerant quantum computation.