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

Published

June 12, 2017

Author(s)

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

Abstract

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)_xNb_y -based barriers, which cannot be explained by the bulk exchange field effect alone. This effect does not originate from the ferromagnetism in (Ni₈₁Fe₁₉)_xNb_y nor is it cumulative with an additional (Ni₈₁Fe₁₉)_xNb_y 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.

Citation

Physical Review Applied

Volume

7

Issue

6

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevApplied.7.064013

Local Download

Keywords

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

Citation

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-(Ni₈₁Fe₁₉)_xNb_y Barriers, Physical Review Applied, [online], https://doi.org/10.1103/PhysRevApplied.7.064013 (Accessed October 9, 2025)