  We study the Josephson transport through ferromagnetic insulators (FIs) by
taking into account its band structure explicitly. In the case of the fully
polarized FIs (FPFIs), we found the formation of a pi-junction and an
atomic-scale 0-pi transition induced by increasing the FI thickness. More
remarkably, in the Josephson junction through spin-filter materials such as Eu
chalcogenides, the orbital hybridization between the conduction d and the
localized f electron gives rise to the pi-junction behavior. Such FI-based
pi-junctions can be used to implement highly-coherent solid-state quantum bits.
