We analyze the quantum state of nanoscale superconducting-magnetic proximity systems with localized or itinerant ferromagnetism. Using the tunable domain wall of an exchange spring and multilayers of misaligned homogeneous ferromagnets, we describe the singlet-triplet pair correlation mixing and current reversal (0- transition) in wide diffusive Josephson junctions. We classify the 0- transitions according to the symmetry of pair correlations involved in the current. In proximity systems with itinerant ferromagnetism, superconducting pair correlations, magnetization, and variation of the charge density are calculated self-consistently.
This model reveals features not seen in the Zeeman exchange model, such as electronic phase separation, or the competition of magnetic and superconducting orders away from the interface.