Quantum anomalous Hall effect in a two-dimensional ferromagnetic NpF monolayer with high Curie temperature

The quantum anomalous Hall (QAH) effect remains a hot topic due to its potential applications in quantum computing and low-energy electronics. Here, based on first-principles calculations and symmetry analysis, we present a new type of two-dimensional (2D) QAH insulator NpF monolayer. Our results show that the NpF monolayer favors ferromagnetic order with high Curie temperature up to 231 K. In the absence of spin-orbit coupling (SOC), the NpF monolayer is a ferromagnetic Weyl semimetal with a nodal loop near the Fermi level. When SOC with out-of-plane magnetization is taken into account, the NpF monolayer becomes a QAH insulator with C = +1, accompanied by a nontrivial band gap of 24.12 meV. When the magnetization lies in-plane and all mirror symmetries are broken, a tunable Chern-number (i.e., C = ±1) phase emerges as a function of azimuthal angles. These discoveries highlight the versatility of QAH platforms and emphasize the interplay between magnetism, topology, and spin-orbit interactions in engineering quantum phases for advanced electronic applications.