Strain-induced two-dimensional topological insulators in monolayer 1T′-RuO2

Because of their unique structure and novel physical properties, two-dimensional (2D) transition metal dichalcogenides (TMDs) have received a lot of attention in recent years. In this paper, we propose a new 2D TMD 1T'-RuO2with tunable topological properties. Based on first-principles calculations, we demonstrate that it has good dynamics, thermodynamic, energetic stability, and anisotropic mechanical properties. Although 1T'-RuO2is a typical semiconductor with a direct bandgap, it can be transformed into topological insulator by applying uniaxial tensile strains. The topological phase transition is attributed to thed-dband inversion at Γ point. The nontrivial topological property is further validated by the topological edge states. We predict that monolayer 1T'-RuO2is an excellent material for future electronic devices with tunable topological properties.