Excellent intrinsic Chern insulators: monolayer PdTaX₂ (X = Se, Te)

Quantum anomalous Hall (QAH) insulators (or Chern insulators) have attracted much attention due to their exotic properties. However the ultra-low critical temperature restricts their potential applications. Based on first-principles calculations, we propose that chalcogenide monolayers PdTaX2 (X = Se, Te) are ferromagnetic Chern insulators with a Chern number of . Their Curie temperatures both exceed 1000 K. Furthermore, the spin-orbit coupling (SOC) induced global band gaps of PdTaSe2 and PdTaTe2 are as large as 350 meV and 566 meV, respectively. The combined merits of high Curie temperature and large nontrivial band gap of PdTaX2 (X = Se, Te) show the potential to break through the critical temperature restriction of QAH. Considering the spin-polarized edge states of PdTaX2 (X = Se, Te), they are also potential candidates for spintronics.