Large critical current density Josephson π -junctions with PdNi barriers

Read full text
Authors: Arjun Sapkota, Pukar Sedai, Robert M. Klaes, R. Loloee, Norman O. Birge, Nathan Satchell
Cited by: 0
References: 52

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