Curvature-induced long-range supercurrents in diffusive superconductor-ferromagnet-superconductor Josephson junctions with a dynamic 0−π transition

Including superconducting components in spintronic devices can improve spin-based data processing by providing dissipationless currents. For impurity-robust conventional s-wave superconductors, a long-ranged proximity effect is typically achieved by generating long-range triplet correlations via magnetic inhomogeneities or intrinsic spin-orbit coupling. We report that spin supercurrents can be induced in diffusive superconductor-ferromagnet-superconductor Josephson junctions without any magnetic misalignment or intrinsic SOC. Instead, the pathway to spin-triplet generation is provided via geometric curvature, and results in a long-range Josephson effect. In addition, the curvature can induce a dynamically tunable 0-π transition in the junction. This switching of current direction is therefore testable in a single sample. These results were first reported in Phys. Rev. B 104, L060505 (2021).