Non-Abelian Fractional Chern Insulators and Competing States in Flat Moiré Bands

Breakthrough experiments have recently realized fractional Chern insulators (FCIs) in moiré materials. However, all states observed are Abelian, the possible existence of more exotic non-Abelian FCIs remains controversial both experimentally and theoretically. Here, we investigate the competition between charge density wave order, gapless composite fermion liquids and non-Abelian Moore-Read states at half-filling of a moiré band. Although groundstate (quasi-)degeneracies and spectral flow is not sufficient for distinguishing between charge order and Moore-Read states, we find evidence using entanglement spectroscopy that both these states of matter can be realized with realistic Coulomb interactions. In a double twisted bilayer graphene model transitions between these phases by tuning the coupling strength between the layers: at weak coupling there is a composite Fermi liquid phase and at strong coupling a low entanglement state signaling CDW order emerges. Remarkably, however, there is compelling evidence for a non-Abelian Moore-Read FCI phase at intermediate coupling.