Critical Current Oscillations of Josephson Junctions Containing PdFe Nanomagnets

Abstract

Josephson junctions with ferromagnetic layers are vital elements in a new class of cryogenic memory devices. One style of memory device contains a spin valve with one "hard" magnetic layer and one "soft" layer. To achieve low switching fields, it is advantageous for the soft layer to have low magnetization and low magnetocrystalline anisotropy. A candidate class of materials that fulfills these criteria is the Pd${}_{1-x}$Fe${}_x$ alloy system with low Fe concentrations. We present studies of micron-scale elliptically-shaped Josephson junctions containing Pd${}_{97}$Fe${}_3$ layers of varying thickness. By applying an external magnetic field, the critical current of the junctions are found to follow characteristic Fraunhofer patterns. The maximum value of the critical current, extracted from the Fraunhofer patterns, oscillates as a function of the ferromagnetic barrier thickness, indicating transitions in the phase difference across the junction between values of zero and $\pi$.

5 pages, 5 figures

References in corpus (4)

• Critical Current Oscillations in Strong Ferromagnetic Pi-Junctions
• Controllable 0-pi Josephson junctions containing a ferromagnetic spin valve
• Ferromagnetic Josephson switching device with high characteristic voltage
• Striking properties of Superconductor/Ferromagnet structures with spin-dependent scattering

Cited by in corpus (10)

• Cryogenic Memory Technologies
• Spin-valve Josephson junctions for cryogenic memory
• Ferromagnetic Materials for Josephson π Junctions
• Magnetic properties of thin epitaxial Pd${}_{1-x}$Fe${}_x$ alloy films
• Ferromagnetic Composite Self-Arrangement in Iron-Implanted Epitaxial Palladium Thin Films
• Ferromagnetic Josephson junctions for cryogenic memory
• Pt and CoB trilayer Josephson $\pi$ junctions with perpendicular magnetic anisotropy
• Manifestations of Spinodal Decomposition into Dilute Pd${}_{1-x}$Fe${}_x$ "Phases" in Iron-Implanted Palladium Films: FMR Study
• Ab initio investigation of impurity ferromagnetism in the Pd1-xFex alloys: concentration and position dependence
• Comparison of NiFeCr and NiFe in ferromagnetic Josephson junctions