Large critical current density Josephson π -junctions with PdNi barriers
Abstract
We report large π-state critical current densities, Jc(π), in Nb/Pd89Ni11/Nb Josephson junctions at Pd89Ni11 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 Pd89Ni11 barrier, we obtain Jc(π)=410 kA/cm2 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 Pd89Ni11 exhibits perpendicular magnetic anisotropy, enabling zero-field operation without magnetic initialization. The combination of large Jc(π) and intrinsic anisotropy establishes Pd89Ni11 as a promising barrier material for passive π-shifters in superconducting digital logic and qubit architectures.
Fields of Study & Subjects
Physics of Superconductivity and Magnetism
Iron-based superconductors research
Superconductivity in MgB2 and Alloys
Publication details
- Journal / source
- Applied Physics Letters
- Volume
- 128
- Issue
- 10
- Publication date
- 9 March 2026
- Language
- EN