Bi₂Te₃-intercalated MnBi₂Te₄: ideal candidate to explore intrinsic Chern insulator and high-temperature quantum...

The recently discovered magnetic topological insulator of MnBi₂Te₄(MBT), has been demonstrated to realize the quantum anomalous Hall (QAH) effect, while the naturally antiferromagnetic (AFM) interlayer coupling in MBT results in that the QAH effect can only be realized in odd-layered systems and at low temperature. Using first-principles calculations, we find that intercalating Bi₂Te₃(BT) layers into MBT by forming MBT/(BT)_n/MBT (n= 1-6) heterostructures can induce magnetic phase transition from AFM to ferromagnetic (FM) interlayer coupling whenn⩾ 3. Specifically, MBT/(BT)₃/MBT and MBT/(BT)₄/MBT respectively host Curie temperaturesT_cof 14 K and 11 K, which fits well the experimentally measuredT_cof 12 K. Detailed band structure calculations and topological identification show that the QAH phases are well preserved for all FM heterostructures. And the topological mechanism of MBT/(BT)_n/MBT as a function ofnis revealed by employing continuum model analysis. Most importantly, the FM MBT/(BT)₄/MBT has already been experimentally fabricated. Thus, our work provides a practical guideline to explore high-temperature QAH effect in MBT family of materials.