Inspired by the recent experimental synthesis of ${\mathrm{Ru}}_2{\mathrm{Si}}_x{\mathrm{O}}_y$ nanosheets derived from the $I4/mmm$ parent compound ${\mathrm{YRu}}_2{\mathrm{Si}}_2$, we study the two-dimensional $\alpha$-PbO ruthenium chalcogenide ($\mathrm{Ru}Ch$) monolayers. We find that while monolayer RuO is unstable, RuS, RuSe, and RuTe exhibit robust thermodynamic and dynamic stability. The electronic structures of these $\mathrm{Ru}Ch$ monolayers closely resemble those of 11-family iron-based superconductors, featuring multiple Fermi surface sheets with hole pockets at the $\mathrm{\Gamma }$ point and electron pockets near the $M$ points, connected by $(\pi ,\pi )$ nesting vectors. Additionally, stabilizing these monolayers on a ${\mathrm{SrTiO}}_3$ (STO) substrate preserves their nesting features, providing an excellent reference for studies on FeSe/STO. By employing effective tight-binding models to explore electron correlation effects, our singular-mode functional renormalization group analysis identifies a predominant $d_{x^2-y^2}$ pairing symmetry. This symmetry, driven by spin fluctuations at the wave vector $(\pi ,\pi )$, remains robust under electron doping. These results suggest that $\mathrm{Ru}Ch$ monolayers share essential features with 11-family Fe-based superconductors and may serve as a platform for exploring RuCh-based high-temperature superconductivity.

Close

PrevNext

View figure in article

• First-principles calculations
• Pairing mechanisms
• Iron-based superconductors
• Two-dimensional electron system