A theoretical proposal of gate-induced quantum anomalous hall effect in 2D ferromagnetic multilayers

The quantum anomalous hall effect (QAHE) is the manifestation of topological electronic structure characterized by a finite Chern number and helical edge electron states and may have potential applications in future electronic devices with low energy consumption. However, the QAHE so far can only be achieved at very low temperatures. Thus, the search for new quantum anomalous hall systems with elevated temperature is in demand. Here we propose a new design based on recently discovered 2D ferromagnetic semiconductors. Using first-principles calculations, we demonstrate that by applying a moderate electric field a 2D ferromagnetic multilayer can be converted into the quantum anomalous hall state. The topological nature and band gap as a function as the applied electric field and film thickness are systematically investigated in details.