A local compressibility study of magic angle twisted bilayer graphene, Part 1*

Magic-angle twisted bilayer graphene (MATBG) exhibits fascinating correlated phases due to the dominance of electronic interactions within its extremely flat low-lying bands. Recent tunneling spectroscopy and magnetotransport experiments have revealed topologically insulating states with Chern number C=±1, 2, 3 at the moiré band filling factors ν=±3, 2, 1, respectively, which are predicted within a minimal model consisting of eight topological bands with C=±1. Here, we report high-resolution local compressibility measurements of MATBG using a scanning single-electron transistor. We identify incompressible states with finite Chern number, and discuss their connection to recent tunneling spectroscopy and magnetotransport results.