Controlling the efficiency of spin injection into graphene by carrier driftJozsa, C., Popinciuc, M., Tombros, N., Jonkman, H. T. & van Wees, B. J., Feb-2009, In : Physical Review. B: Condensed Matter and Materials Physics. 79, 8, p. 081402-1-081402-4 4 p., 081402.
Research output: Contribution to journal › Article › Academic › peer-review
Electrical spin injection from ferromagnetic metals into graphene is hindered by the impedance mismatch between the two materials. This problem can be reduced by the introduction of a thin tunnel barrier at the interface. We present room-temperature nonlocal spin valve measurements in cobalt/aluminum-oxide/graphene structures with an injection efficiency as high as 18%, where electrical contact is achieved through relatively transparent regions in the oxide. This value is further enhanced to 31% by applying a dc current bias on the injector electrodes, which causes carrier drift away from the contact. A reverse bias reduces the ac spin valve signal to zero or negative values. We introduce a model that quantitatively predicts the behavior of the spin accumulation in the graphene under such circumstances, showing a good agreement with our measurements.
|Number of pages||4|
|Journal||Physical Review. B: Condensed Matter and Materials Physics|
|Publication status||Published - Feb-2009|
- aluminium compounds, carbon, cobalt, electrical contacts, ferromagnetic materials, nanostructured materials, spin valves, ROOM-TEMPERATURE