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

Abstract

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.