Mapping twist-tuned multiband topology in bilayer WSe_2

Semiconductor moiré superlattices have been shown to host a wide array of interaction-driven ground states. However, twisted homobilayers have been difficult to study in the limit of large moiré wavelength, where interactions are most dominant. Here, we conduct local electronic compressibility measurements of twisted bilayer WSe_2 (tWSe_2) at small twist angles. We demonstrate multiple topological bands which host a series of Chern insulators at zero magnetic field near a 'magic angle' around 1.23^∘. Using a locally applied electric field, we induce a topological quantum phase transition at one hole per moiré unit cell. Our work establishes the topological phase diagram of a generalized Kane-Mele-Hubbard model in tWSe_2, demonstrating a tunable platform for strongly correlated topological phases.