Nematic superconductivity in magic-angle twisted bilayer graphene from atomistic modeling

Using full-scale atomistic modeling with local electronic interactions, this study reveals a highly inhomogeneous superconducting state with nematic ordering in twisted bilayer graphene (TBG) at and above experimentally relevant temperatures. The nematic state exhibits locally anisotropic real-valued d-wave pairing, with a nematic vector winding throughout the moiré pattern and threefold degeneracy. Despite d-wave symmetry, a full energy gap is observed, attributed to π-phase interlayer coupling. Superconducting nematicity is directly detectable in the local density of states. The results highlight the importance of atomistic modeling and reveal differences in superconducting states between TBG and high-temperature cuprate superconductors despite similar local interactions.

Tomas Löthman, Johann Schmidt, Fariborz Parhizgar, Annica M. Black-Schaffer