Magnetization-driven quantum anomalous Hall effect and topological transitions in monolayer T-RuO2

Two-dimensional topological insulators exhibit dissipationless boundary states, enabling breakthroughs in high-speed, low-power electronics. This study investigates monolayer T-RuO₂ as a novel tunable magnetic topological material using first-principles calculations. T-RuO₂ intrinsically exhibits in-plane ferromagnetic ordering but remains topologically trivial. Notably, when the magnetization tilts out of the plane, it undergoes a topological phase transition, entering a non-trivial state with a Chern number of C = −2, thereby realizing the quantum anomalous Hall effect (QAHE). Furthermore, applying 0 %–2 % in-plane biaxial tensile strain enables precise control over the magnetization deflection required for this transition. The notable robustness of the topological properties of T-RuO₂ under various deformations suggests its potential as a stable and reliable candidate for next-generation quantum devices.