Topological Superconductivity in Twisted Multilayer Graphene

Understand

We study a minimal Hubbard model for electronically driven superconductivity in a correlated flat mini-band resulting from the superlattice modulation of a twisted graphene multilayer.

• The valley degree of freedom drastically modifies the nature of thepreferred pairing states, favoring spin triplet $d+id$ order with a valley singlet structure.
• We identify two candidates in this class, which are both topological superconductors.
• These states support half-vortices carrying half the usual superconducting flux quantum $hc/(4e)$, and have topologically protected gapless edge states.