High Chern number quantum anomalous Hall effect in monolayer Co3X3SSe (X = Sn, Pb) kagomes

Abstract

The high Chern number quantum anomalous Hall effect can offer an ideal platform to develop exotic quantum materials with a dissipationless chiral edge. The investigation of kagome monolayer Co₃X₃SSe (X = Sn, Pb) materials enables a comprehensive exploration of their structural, magnetoelectric, and topological characteristics through first-principles calculations. The monolayers Co₃Sn₃SSe and Co₃Pb₃SSe are classified as kagome ferromagnets, and they exhibit stable perpendicular magnetic anisotropy energy. These materials can achieve the intrinsic high Chern number quantum anomalous Hall effect with C = −3. The band gaps of Co₃Sn₃SSe and Co₃Pb₃SSe are 46 and 59 meV, respectively, which are larger than the thermal energy at room-temperature scale. Additionally, our findings demonstrate that both the band gap and magnetic anisotropy energy of the monolayers Co₃Sn₃SSe and Co₃Pb₃SSe are sensitive to applied strain. This research presents intriguing and alternative possibilities for advancing intrinsic high Chern number quantum anomalous Hall devices.