Phase Offsets in the Critical-Current Oscillations of Josephson Junctions Based on Ni and Ni- (Ni81Fe19)xNby Barriers

Superconducting and magnetic materials can be used together to access the spintronic aspects of the superconducting order. By inserting either a magnetic or nonmagnetic alloy layer into ferromagnetic Josephson junctions, the authors reveal a qualitative change in the characteristics of critical-current oscillation that is not explained by conventional theory. Their observations indicate that superconducting memory based on a spin valve cannot be properly understood or designed without an added phase offset.