Large critical current density Josephson $π$ junctions with PdNi barriers
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866914419387138048 |
|---|---|
| author | Sapkota, Arjun Sedai, Pukar Klaes, Robert M. Loloee, Reza Birge, Norman O. Satchell, Nathan |
| author_facet | Sapkota, Arjun Sedai, Pukar Klaes, Robert M. Loloee, Reza Birge, Norman O. Satchell, Nathan |
| contents | We report large $π$-state critical current densities, $J_c(π)$, in Nb/Pd$_{89}$Ni$_{11}$/Nb Josephson junctions at Pd$_{89}$Ni$_{11}$ thicknesses near the first $π$-state. We observe oscillations in the critical current with ferromagnetic barrier thickness consistent with a $0$-$π$ transition. For a junction with a 9.4~nm Pd$_{89}$Ni$_{11}$ barrier, we obtain $J_c(π) = 410~\mathrm{kA/cm^{2}}$ at 4.2~K, exceeding values reported in prior PdNi-based studies. Magnetization measurements on continuous films, together with coercivity tests on patterned arrays, confirm that Pd$_{89}$Ni$_{11}$ exhibits perpendicular magnetic anisotropy, enabling zero-field operation without magnetic initialization. The combination of large $J_c(π)$ and intrinsic anisotropy establishes Pd$_{89}$Ni$_{11}$ as a promising barrier material for passive $π$-shifters in superconducting digital logic and qubit architectures. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2505_03913 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Large critical current density Josephson $π$ junctions with PdNi barriers Sapkota, Arjun Sedai, Pukar Klaes, Robert M. Loloee, Reza Birge, Norman O. Satchell, Nathan Superconductivity Mesoscale and Nanoscale Physics We report large $π$-state critical current densities, $J_c(π)$, in Nb/Pd$_{89}$Ni$_{11}$/Nb Josephson junctions at Pd$_{89}$Ni$_{11}$ thicknesses near the first $π$-state. We observe oscillations in the critical current with ferromagnetic barrier thickness consistent with a $0$-$π$ transition. For a junction with a 9.4~nm Pd$_{89}$Ni$_{11}$ barrier, we obtain $J_c(π) = 410~\mathrm{kA/cm^{2}}$ at 4.2~K, exceeding values reported in prior PdNi-based studies. Magnetization measurements on continuous films, together with coercivity tests on patterned arrays, confirm that Pd$_{89}$Ni$_{11}$ exhibits perpendicular magnetic anisotropy, enabling zero-field operation without magnetic initialization. The combination of large $J_c(π)$ and intrinsic anisotropy establishes Pd$_{89}$Ni$_{11}$ as a promising barrier material for passive $π$-shifters in superconducting digital logic and qubit architectures. |
| title | Large critical current density Josephson $π$ junctions with PdNi barriers |
| topic | Superconductivity Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2505.03913 |