The manipulations of light-induced chiral edge states in monolayer noncollinear antiferromagnet Sc3C6O6

The quantum anomalous Hall effect (QAHE) is a hallmark of topological quantum states, which has attracted significant attention due to its dissipationless transport characteristics. This study theoretically investigates the dynamic modulation of QAHE in two-dimensional noncollinear antiferromagnetic (NAFM) kagome organic–metal framework Sc3C6O6 under both resonant and non-resonant schemes via Floquet engineering. First-principles calculations demonstrate that in monolayer Sc3C6O6, the NAFM state exhibits superior magnetic stability compared to the collinear ferromagnetic state, while possessing a symmetry-protected Dirac point below the Fermi level, and this characteristic differentiates it from the lower-energy but topologically trivial antiferromagnetic state. Circularly polarized light (CPL) dynamically breaks mirror symmetry (M), thereby opening a topologically non-trivial bandgap and generating quantized anomalous Hall conductance. By rotating the magnetic moments, we obtained three typical configurations: Type-I (e.g., ϕ=0°) exhibits stable QAHE; Type-II (e.g., ϕ=60°) is topologically trivial; Type-III (e.g., ϕ=150°) enables optically tunable edge states. Further investigation under low-energy CPL (ℏω=0.2 eV) reveals chiral-inverted edge channels and higher optical modulation sensitivity, with the required light intensity for quantization reduced by 25% compared to the high-energy regime. Notably, the propagation direction of the surface states is strictly locked to the light helicity; switching the chirality of circular polarization enables reversal of both the edge state direction and the sign of the Chern number. This work establishes Sc3C6O6 as an ideal NAFM platform for studying non-equilibrium topological states and provides a feasible strategy for manipulating QAHE in frustrated magnets. This work establishes Sc3C6O6 as an ideal NAFM platform for studying non-equilibrium topological states and provides a feasible strategy for manipulating QAHE in frustrated magnets.