Topology of twisted BSCCO

Twisted two-dimensional electronic systems are being extensively studied for realizing exotic correlated insulators and paired states. Recently, twisted bilayers of BSCCO have been proposed as material candidates for realizing time-reversal-symmetry-breaking paired states. Motivated by such proposals, we investigate topological properties of possible paired states, using a combined analysis of momentum-space invariants and real-space topological response. Apart from identifying ground states supporting net Chern numbers, we also characterize topologically non-trivial states with vanishing net Chern numbers. The employed theoretical framework is suitable for addressing the effects of electronic correlations and competing orders.