Room Temperature Quantum Anomalous Hall Insulator in a Honeycomb-Kagome Lattice, Ta₂O₃, with Huge Magnetic Anisotropy Energy

The quantum anomalous Hall (QAH) effect has attracted enormous attention since it can induce topologically protected conducting edge states in an intrinsic insulating material. For practical quantum applications, the main obstacle is the non-existent room temperature QAH systems, especially with both large topological band gap and robust ferromagnetic order. Here, based on first-principles calculations, we predict the realization of the room temperature QAH effect in a two-dimensional honeycomb-Kagome (HK) lattice, Ta2O3, which is a QAH insulator with a non-zero Chern number of C =-1. We further found that the non-trivial topological properties are robust against the biaxial strain, where the band gap increases from 80.5 up to 454.8 meV with the strain increasing from 0 to 6%. Moreover, we find that Ta2O3 has a huge magnetic anisotropy energy (42.8 meV) and unusual high Curie temperature (788 K). The robust topological and magnetic properties make Ta2O3 have great application potentials in room temperature spintronics and nanoelectronics.