Moiré systems made from stacked two-dimensional materials host correlated and topological states that can be electrically controlled with applied gate voltages. One prevalent form of topological state that can occur are Chern insulators that display a quantum anomalous Hall effect. Here we manipulate Chern domains in an interaction-driven quantum anomalous Hall insulator made from twisted monolayer–bilayer graphene and observe chiral interface states at the boundary between different domains. By tuning the carrier concentration, we stabilize neighbouring domains of opposite Chern number that then provide topological interfaces devoid of any structural boundaries. This allows the wavefunction of chiral interface states to be directly imaged using a scanning tunnelling microscope. Our theoretical analysis confirms the chiral nature of observed interface states and allows us to determine the characteristic length scale of valley polarization reversal across neighbouring Chern domains.

由堆叠的二维材料制成的莫尔系统具有相关的拓扑状态，可以通过施加的栅极电压进行电控制。一种常见的拓扑状态形式是陈绝缘体，它表现出量子反常霍尔效应。在这里，我们操纵由扭曲单层-双层石墨烯制成的相互作用驱动的量子反常霍尔绝缘体中的陈畴，并观察不同畴之间边界的手性界面态。通过调整载流子浓度，我们稳定了相反陈数的相邻域，然后提供没有任何结构边界的拓扑界面。这使得可以使用扫描隧道显微镜直接对手性界面态的波函数进行成像。我们的理论分析证实了观察到的界面态的手性性质，并使我们能够确定相邻陈域之间谷极化反转的特征长度尺度。