  Moir\'e systems made from stacked two-dimensional materials host novel
correlated and topological states that can be electrically controlled via
applied gate voltages. We have used this technique to manipulate Chern domains
in an interaction-driven quantum anomalous Hall insulator made from twisted
monolayer-bilayer graphene (tMBLG). This has allowed the wavefunction of chiral
interface states to be directly imaged using a scanning tunneling microscope
(STM). To accomplish this tMBLG carrier concentration was tuned to stabilize
neighboring domains of opposite Chern number, thus providing topological
interfaces completely devoid of any structural boundaries. STM tip
pulse-induced quantum dots were utilized to induce new Chern domains and
thereby create new chiral interface states with tunable chirality at
predetermined locations. Theoretical analysis confirms the chiral nature of
observed interface states and enables the determination of the characteristic
length scale of valley polarization reversal across neighboring tMBLG Chern
domains. tMBLG is shown to be a useful platform for imaging the exotic
topological properties of correlated moir\'e systems.
