Controllable supercurrent in mesoscopic superconductor-normal metal-ferromagnet crosslike Josephson structures

TL;DR

This paper reports experimental observation and theoretical modeling of controllable supercurrent behavior in mesoscopic S-N/F-S Josephson structures, highlighting the effects of spin injection and Zeeman splitting on supercurrent transitions.

Contribution

It introduces a combined experimental and theoretical study of supercurrent control via spin injection and magnetic effects in S-N/F-S Josephson junctions, revealing nonmonotonic critical current dependence.

Findings

Nonmonotonic critical supercurrent observed experimentally.

Model explains 0-pi and pi-0 transitions due to spin and Zeeman effects.

Qualitative agreement between experiment and theory achieved.

Abstract

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-pi and pi-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 structure and the spin-dependent double-step nonequilibrium quasiparticle distribution.