Layer-dependent and gate-tunable Chern numbers in 2D kagome ferromagnet Yb2(C6H4)3 with a large band gap

The chiral edge states in the quantum anomalous Hall effect enable dissipationless longitudinal transport without requiring an external magnetic field, making them promising for the realization of low-power, high-speed electronic devices. However, realizing high-Chern-number quantum anomalous Hall effect with tunable edge channels and large band gaps remains challenging. Here, we propose a stable two-dimensional monolayer kagome ferromagnet, Yb 2 (C 6 H 4 ) 3 , as a quantum anomalous Hall insulator with a band gap of 102.4 meV and a non-trivial Chern number \({\mathcal{C}}=-1\) . Through AB-stacking of monolayer Yb 2 (C 6 H 4 ) 3 , the material can exhibit tunable high Chern numbers (for example, \({\mathcal{C}}=-2\) for the bilayer) due to ferromagnetic interlayer interactions, thereby providing additional conducting channels. Additionally, these Chern numbers can be effectively modulated by an external electric field, enabling devices with electric-field-controllable conductance. This dual tunability-through both layer stacking and electric gating-establishes Yb 2 (C 6 H 4 ) 3 as a potential platform for high-temperature, multi-channel topological electronics.