Abstract
Utilizing a full microscopic Bogoliubov–de Gennes (BdG) approach, we study the equilibrium charge and spin currents in ballistic SFSFS Josephson systems, where F is a uniformly magnetized ferromagnet and S is a conventional s-wave superconductor. From the spatially varying spin currents, we also calculate the associated equilibrium spin-transfer torques. Through variations in the relative phase differences between the three S regions, and magnetization orientations of the ferromagnets, our study demonstrates tunability and controllability of the spin and charge supercurrents. The spin-transfer torques are shown to reveal details of the proximity effects that play a crucial role in these types of hybrid system. The proposed SFSFS nanostructure is discussed within the context of a superconducting magnetic torque transistor.
Highlights
Proximity effects inherent to superconducting systems with inhomogeneous magnetic order presents a mechanism by which dissipationless current flow and the spin degree-offreedom can both be effectively coupled and controlled.[1,2,3,4,5,6] The important role that proximity effects play in the static and transport properties of ferromagnetic Josephson junctions with s-wave superconductors is well established
The focus of this paper is to theoretically investigate proximity effects leading to modified superconducting correlations and controlled charge and spin transport in S FS FS ballistic junctions
We present a study of the crossover between the first and second harmonic in the current phase relations and consider experimentally feasible situations to observe them
Summary
Proximity effects inherent to superconducting systems with inhomogeneous magnetic order presents a mechanism by which dissipationless current flow and the spin degree-offreedom can both be effectively coupled and controlled.[1,2,3,4,5,6] The important role that proximity effects play in the static and transport properties of ferromagnetic Josephson junctions with s-wave superconductors is well established. The spin angular momentum of the polarized current will be partially transferred to the magnetization in the F region.[19,20] This spin transfer torque (STT) serves as an important mechanism in spintronics devices.[19,20,21] The STT effect can cause magnetization switching for sufficiently large currents without the need for an external field. This switching aspect provides a unique opportunity to create and improve fast-switching magnetic random access memories.[22,23,24,25]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
