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



Burm Baek, Michael L. Schneider, Matthew R. Pufall, William H. Rippard


We measure and compare the critical-current oscillation characteristics of Josephson junctions as a function of Ni thickness in different barrier structures. The characteristics dependent on the relative Ni thickness, such as the presence of nodes and the oscillation period, are consistent with a conventional, clean-limit magnetic Josephson-junction model. However, the oscillation phases have different offsets in the Ni thickness between single Ni and Ni-(Ni81Fe19)xNby -based barriers, which cannot be explained by the bulk exchange field effect alone. This effect does not originate from the ferromagnetism in (Ni81Fe19)xNby nor is it cumulative with an additional (Ni81Fe19)xNby layer. Our results present clear evidence that a nonmagnetic layer can affect the superconducting spin phase across the junction as strongly as the conventional exchange field effect.
Physical Review Applied


oscillation characteristics, Josephson junctions, Ni, barrier structures, superconductivity, magnetism, cryogenic memory, proximity effect, spin phase, conventional exchange field effect


Baek, B. , Schneider, M. , Pufall, M. and Rippard, W. (2017), Phase Offsets in the Critical-Current Oscillations of Josephson Junctions Based on Ni and Ni-(Ni<sub>81</sub>Fe<sub>19</sub>)<sub>x</sub>Nb<sub>y</sub> Barriers, Physical Review Applied, [online], (Accessed April 14, 2024)
Created June 12, 2017, Updated June 26, 2020