  Motivated by the recent achievements in the realization of strongly
correlated and topological phases in twisted van der Waals heterostructures, we
study the low-energy properties of a twisted bilayer of nodal superconductors.
It is demonstrated that the spectrum of the superconducting Dirac
quasiparticles close to the gap nodes is strongly renormalized by twisting and
can be controlled with magnetic fields, current, or interlayer voltage. In
particular, 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. 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.
