  We consider s-wave pairing in a double layer of two chiral metals due to
Coulomb interaction, and study the Josephson effect near a domain wall, where
the sign of the order parameter jumps. The domain wall creates two zero energy
modes, whose superposition is associated with a current that flows in different
direction in the two layers. Assuming a toroidal geometry, the effective
Josephson currents winds around the domain walls, whose winding number is
determined by the coefficients of the superimposed zero energy modes. This
result can be understood as a competition of the conventional Josephson current
perpendicular and the edge current parallel to a domain wall in a double layer
of two chiral metals. As a realization we suggest the surface of a ring-shaped
topological insulator. The duality between electron-electron and electron-hole
double layers indicates that this effect should also be observable in excitonic
double layers.
