Externally controlled selective spin transfer through a two-terminal bridge setup

A new way of getting controlled spin dependent transport through a two-terminal bridge setup is explored. The system comprises a magnetic quantum ring which is directly coupled to a magnetic quantum wire and subjected to an in-plane electric field perpendicular to the wire. Without directly changing system parameters, one can regulate spin currents simply by tuning the external electric field under a finite bias drop across the wire. For some particular field strengths a high degree of spin polarization can be achieved and thus the system can essentially be utilized as an externally controlled spin polarized device. A detailed comparison of spin current magnitudes obtained from other bridge setups is also examined to make the present investigation a self contained study.