Regensburg 2013 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 48: Spin-dependent Transport Phenomena

MA 48.11: Vortrag

Freitag, 15. März 2013, 12:15–12:30, H23

Exploiting spin extraction for local spin valve structures — •Yori Manzke, Rouin Farshchi, Pawel Bruski, Jens Herfort, and Manfred Ramsteiner — Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany

We show that spin extraction [1] can serve as the spin generation mechanism in local spin valves. In contrast to electrical spin injection, which is commonly employed in such magnetoresistance devices, spin accumulation in a non-magnetic semiconductor (SC) is created upon an electron flow from the SC into a ferromagnetic metal Schottky contact. The investigated samples comprise ferromagnetic Heusler alloy (Co₂FeSi) contact stripes on an n-type GaAs channel. A current divider arrangement is used to generate spin polarized drift currents by spin extraction and to sense spin-induced changes in contact resistance at a subsequent ferromagnetic stripe. We discuss the extension of this scheme to spin valves based on multiple extraction events. Generally, the electrical output signal of our magnetoresistance devices depends on the relative orientation of the contact magnetizations and we obtain 2^m−1 electrical output states for m ferromagnetic contacts. Our results suggest that multiple spin extraction may find its application in the generation of highly spin-polarized drift currents and as a read-out mechanism in magnetic data storage. This work was partially supported by the DFG via SPP 1538.
[1] J. Stephens et al., Phys. Rev. Lett. 93, 097602 (2004).