Pt and CoB trilayer Josephson $\pi$ junctions with perpendicular magnetic anisotropy

Abstract

We report on the electrical transport properties of Nb based Josephson junctions with Pt/Co${}_{68}$B${}_{32}$/Pt ferromagnetic barriers. The barriers exhibit perpendicular magnetic anisotropy, which has the main advantage for potential applications over magnetisation in-plane systems of not affecting the Fraunhofer response of the junction. In addition, we report that there is no magnetic dead layer at the Pt/Co${}_{68}$B${}_{32}$ interfaces, allowing us to study barriers with ultra-thin Co${}_{68}$B${}_{32}$. In the junctions, we observe that the magnitude of the critical current oscillates with increasing thickness of the Co${}_{68}$B${}_{32}$ strong ferromagnetic alloy layer. The oscillations are attributed to the ground state phase difference across the junctions being modified from zero to $\pi$. The multiple oscillations in the thickness range $0.2⩽d_{\text{CoB}}⩽1.4$~nm suggests that we have access to the first zero-$\pi$ and $\pi$-zero phase transitions. Our results fuel the development of low-temperature memory devices based on ferromagnetic Josephson junctions.

arXiv commentMain text: 11 pages, 3 figures, 1 table. Supplementary information: 9 pages, 5 figures

References in corpus (42)

• Proximity effects in superconductor-ferromagnet heterostructures
• Odd Triplet Superconductivity and Related Phenomena in Superconductor-Ferromagnet Structures
• Coupling of two superconductors through a ferromagnet : evidence for a pi-junction
• Superconducting Spintronics
• Spin-polarized supercurrents for spintronics: a review of current progress
• Hybrid superconducting-magnetic memory device using competing order parameters
• Critical Current Oscillations in Strong Ferromagnetic Pi-Junctions
• Controllable 0-pi Josephson junctions containing a ferromagnetic spin valve
• Josephson current in superconductor-ferromagnet structures with a nonhomogeneous magnetization
• Oscillations of the superconducting critical current in Nb-Cu-Ni-Cu-Nb junctions
• Spin-orbit coupling as a source of long-range triplet proximity effect in superconductor-ferromagnet hybrid structures
• Rashba Effect at Magnetic Metal Surfaces
• 0-pi Josephson tunnel junctions with ferromagnetic barrier
• High quality ferromagnetic 0 and pi Josephson tunnel junctions
• Diameter-independent skyrmion Hall angle in the plastic flow regime observed in chiral magnetic multilayers
• Controllable Josephson current through a pseudo-spin-valve structure
• Observation of Periodic pi-Phase Shifts in Ferromagnet-Superconductor Multilayers
• Josephson tunnel junctions with strong ferromagnetic interlayer
• Critical Current Behavior in Josephson Junctions with the Weak Ferromagnet PdNi
• Experimental demonstration of a Josephson magnetic memory cell with a programmable π-junction
• Striking properties of Superconductor/Ferromagnet structures with spin-dependent scattering
• Anomalous current in diffusive ferromagnetic Josephson junctions
• Deterministic field-free skyrmion nucleation at a nano-engineered injector device
• Characteristics of strong ferromagnetic Josephson junctions with epitaxial barriers
• Spin-valve Josephson junctions for cryogenic memory
• Second-harmonic current-phase relation in Josephson junctions with ferromagnetic barriers
• Supercurrent in ferromagnetic Josephson junctions with heavy metal interlayers
• Charge and Spin Currents in Ferromagnetic Josephson junctions
• Spin Triplet Supercurrent in Co/Ni Multilayer Josephson Junctions with Perpendicular Anisotropy
• Josephson Junctions with a synthetic antiferromagnetic interlayer
• Phase Control in a Spin-Triplet SQUID
• Threshold Interface Magnetization Required to Induce Magnetic Proximity Effect
• Phase Controllable Josephson Junctions for Cryogenic Memory
• Area-dependence of spin-triplet supercurrent in ferromagnetic Josephson junctions
• 0-pi oscillations in nanostructured Nb/Fe/Nb Josephson junctions
• Supercurrent in ferromagnetic Josephson junctions with heavy metal interlayers. II. Canted magnetization
• Critical Current Oscillations of Elliptical Josephson Junctions with Single-Domain Ferromagnetic Layers
• Superconductor-insulator-ferromagnet-superconductor Josephson junction: From the dirty to the clean limit
• Critical Current Oscillations of Josephson Junctions Containing PdFe Nanomagnets
• Spin-valve Josephson junctions with perpendicular magnetic anisotropy for cryogenic memory
• Spin-triplet supercurrent in Josephson junctions containing a synthetic antiferromagnet with perpendicular magnetic anisotropy
• Distortions to the penetration depth and coherence length of superconductor/normal-metal superlattices

Cited by in corpus (7)

• Ferromagnetic Materials for Josephson π Junctions
• Superconductivity assisted change of the perpendicular magnetic anisotropy in V/MgO/Fe junctions
• Upper critical fields in normal metal-superconductor-normal metal trilayers
• Reduced decay in Josephson coupling across ferromagnetic junctions with spin-orbit coupling layers
• Comparison of NiFeCr and NiFe in ferromagnetic Josephson junctions
• Large critical current density Josephson $\pi$ junctions with PdNi barriers
• Reversible Magneto-ionic Modification of Metallic Magnetic Thin Films