A type II superconducting film with a transverse magnetic field, in contact with a topological insulator, has a Majorana fermion at the centre of every vortex core. A realistic model has a hopping term and a short-range interaction term for the Majorana fermions. By adjusting a chemical potential for the topological insulator, it is possible to tune the hopping term to zero, so that the interaction strength to hopping strength ratio goes too infinity. Adjusting this ratio leads to a fascinating phase diagram which I will discuss in both 1 and 2 dimensions. A supersymmetric phase is shown to occur in both cases.
