BdG equations within lattice Hubbard model for the description of $\pi$-states in nanoscale S-FF-S junctions

N. Stefanakis

We calculate the persistent currents in $S-F_{\uparrow }{F}_{\uparrow [\downarrow ]}-S$ structures (S denotes the superconductor in a closed ring geometry, F the ferromagnet in a two di…