Twisted Nodal Superconductors

arXiv:2012.07860

Momentum space schematic of a twisted nodal superconductor appropriate for high-Tc cuprate bilayer. Inset shows the current-induced opening of a topological gap.

Motivated by the recent achievements in the realization of strongly correlated and topological phases in twisted van der Waals heterostructures, we have studied the low-energy properties of a twisted bilayer of nodal superconductors. The highlight of the work is that the application of an interlayer current transforms the system into a topological superconductor, opening a topological gap and resulting in a quantized thermal Hall effect with gapless, neutral edge modes. Additionally, close to the “magic angle,” where the Dirac velocity of the quasiparticles is found to vanish, a correlated superconducting state breaking time-reversal symmetry is shown to emerge. Estimates for a number of superconducting materials, such as cuprate, heavy fermion, and organic nodal superconductors, show that twisted bilayers of nodal superconductors can be readily realized with current experimental techniques.

arXiv:2012.07860

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