  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.
