Quantum anomalous Hall states enriched by asynchronous mass inversion in multilayer graphene
摘要
Recently, multilayer graphene systems have attracted significant attention due to the discovery of many intriguing phases, particularly quantum anomalous Hall (QAH) states. In rhombohedral pentalayer graphene, QAH states with Chern numbers C = − 5 and C = − 3 have been observed, but the origin of the C = − 3 state remains unclear. Here we show that trigonal warping, staggered layer order, and displacement field together generate an asynchronous mass inversion mechanism. Trigonal warping splits the low-energy bands into one central touching point and three satellite Dirac cones, while the coexistence of staggered layer order and displacement field produces a momentum-dependent mass term. In rhombohedral pentalayer graphene, as the displacement field increases, mass inversion occurs first at the satellite cones and then at the central touching point, yielding the C = − 3 state and the subsequent transition to C = − 5. This mechanism also explains the observed C = 6 state in Bernal-stacked tetralayer graphene, guiding future experiments to engineer tunable high-Chern phases.