Origin of Spontaneous Currents in a Superconductor-Ferromagnet Proximity   System
  We have previously shown that a ferromagnet-superconductor heterostructure may possess a spontaneous current circulation parallel to the interface. This current is caused by Andreev bound states in the thin ferromagnetic layer, and can be fully spin-polarized. Here we investigate the total energy of the system in cases where the current either does or does not flow. We show that the current is a true quantum ground state effect, and examine the effect of the current on the different contributions to the total energy. 
J. F. Annett, M. Krawiec and B. L. Gyorffy