DMRG evidence for superconductivity via skyrmion-condensation: Application to magic angle graphene*

We numerically study the fate of interacting electrons in tunnel-coupled spinful Chern bands with opposite Chern numbers using density-matrix renormalization group (DMRG). Such a model has been argued to capture the essential symmetries and band topology of magic angle twisted bilayer graphene. On doping away from the antiferromagnetic insulator at charge neutrality, we find a superconducting ground state, although the inter-electronic interaction is purely repulsive. By studying the energetics of charged excitations, we establish that superconductivity is driven by the binding of electrons into charge-2e bosonic skyrmions which subsequently condense. This binding is observed even in the regime where the Coulomb repulsion is by-far the largest energy scale, demonstrating the robustness of this topological, all-electronic pairing mechanism.