Prediction of high-Tc phonon-mediated superconductivity with strong Ising spin-orbit coupling in monolayer WNO

Abstract

The Ising superconductor, due to its unique upper critical magnetic field, has become one of the most prominent subjects in the field of two-dimensional materials in recent years. Currently, the researches on Type I Ising superconductors mainly focus on transition metal chalcogenides (TMDs), however, the limited superconducting transition temperature (T_c) restricts their practical application. In addition to TMDs, Janus materials with central inversion symmetry breaking are also promising candidates for possessing strong Ising spin orbital couple (SOC). Here, through high-throughput calculations of T-phase and H-phase Janus materials transition metal nitrogen oxides (TMNOs), we obtain a potential high-T_c superconductor H-WNO. By solving the anisotropic Eliasberg equation, its T_c is predicted to be 46 K with strong electron phonon coupling of 1.71. Further calculations show that its Ising SOC is much stronger than Rashba SOC, and its average spin-orbit splitting energy at the Fermi level is comparable to that of the well-known Ising superconductor NbSe₂, indicating that WNO is a potential excellent Ising superconductor. This is the first time that a Janus superconductor with high-T_c and strong Ising SOC was predicted. Our work opens up a new field to searching for high-T_c Ising superconductors.