We study theoretically spontaneous currents and magnetic field induced in a superconductor-ferromagnet (S-F) bilayer due to direct and inverse proximity effects. The induced currents { are Meissner currents that appear even in the absence of an external magnetic field due to the magnetic moment in the ferromagnet }and { to the magnetization } in the superconductor . The latter is induced by the inverse proximity effect over a distance of the order of the superconducting correlation length $\xi _{ S}$. On the other hand the magnetic induction $B$, caused by Meissner currents, penetrates the S film over the London length $\lambda _{ S}$. Even though $\lambda _{ S}$ usually exceeds considerably the correlation length, the amplitude and sign of $B$ at distances much larger than $\xi _{ S}$ depends crucially on the strength of the exchange energy in the ferromagnet and on the magnetic moment induced in the in the S layer.
Categories: cond-mat.supr-con cond-mat.mes-hall