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)=410kA/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.
@article{arxiv.2505.03913,
title = {Large critical current density Josephson $\pi$ junctions with PdNi barriers},
author = {Arjun Sapkota and Pukar Sedai and Robert M. Klaes and Reza Loloee and Norman O. Birge and Nathan Satchell},
journal= {arXiv preprint arXiv:2505.03913},
year = {2026}
}