Controllable supercurrent in mesoscopic superconductor-normal metal-ferromagnet crosslike Josephson structures
A nonmonotonic dependence of the critical Josephson supercurrent on the injection current
through a normal metal/ferromagnet weak link from a single domain ferromagnetic strip has
been observed experimentally in nanofabricated planar crosslike S-N/F-S Josephson structures.
This behavior is explained by 0–π and π–0 transitions, which can be caused by the suppression
and Zeeman splitting of the induced superconductivity due to interaction between N and F
layers, and the injection of spin-polarized current into the weak link. A model considering both
effects has been developed. It shows the qualitative agreement between the experimental results
and the theoretical model in terms of spectral supercurrent-carrying density of states of S-N/F-S
structures and the spin-dependent double-step nonequilibrium quasiparticle distribution.