  We study the effect of coupling between the superconducting current and
magnetization in the superconductor/ferromagnet/superconductor Josephson
junction under an applied circularly polarized magnetic field. Manifestation of
ferromagnetic resonance in the frequency dependence of the amplitude of the
magnetization and the average critical current density is demonstrated
numerically. The IV-characteristics show subharmonic steps that form devil's
staircases, following a continued fraction algorithm. The origin of the found
steps is related to the effect of the magnetization dynamics on the phase
difference in the Josephson junction. The dynamics of our system is described
by a generalized RCSJ model coupled to the Landau-Lifshitz-Gilbert equation. In
the suplement we justify analytically the appearance of the fractional steps in
IV-characteristics of the superconductor/ferromagnet/superconductor Josephson
junction.
