Magnetization control of the critical current in a S-(S/F)-S superconducting switch

Abstract

We show the control of the critical current Ic of a superconductor–superconductor/ferromagnet–superconductor [S-(S/F)-S] type switch by the magnetization state of the F. The inverse proximity effect of a S/F bilayer is used to define the weak link and hence the maximum critical current of the junction. The magnetization of the F lead is set by an external magnetic field. We show that the critical current in zero field depends on the remanent magnetization state via stray-field effects and thereby allows for a post-manufacturing control of the junction's properties, in particular the tunability between a maximal critical current and a full suppression of Ic without applying a persistent magnetic field. We propose a simplified model based on the relative orientation of magnetic domains that explains our findings qualitatively.