Current- and field-induced topology in twisted nodal superconductors

We show that interlayer current induces topological superconductivity in twisted bilayers of nodal superconductors. A bulk gap opens and achieves its maximum near a ``magic’’ twist angle ${\theta }_{\mathrm{M}\mathrm{A}}$. Chiral edge modes lead to a quantized thermal Hall effect at low temperatures. Furthermore, we show that an in-plane magnetic field creates a periodic lattice of topological domains with edge modes forming low-energy bands. We predict their signatures in scanning tunneling microscopy. Estimates for candidate materials indicate that twist angles $\theta \sim {\theta }_{\mathrm{M}\mathrm{A}}$ are optimal for observing the predicted effects.