Controlling the efficiency of spin injection into graphene by carrier drift

C. Jozsa*, M. Popinciuc, N. Tombros, H. T. Jonkman, B. J. van Wees

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

73 Citaten (Scopus)
262 Downloads (Pure)


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.

Originele taal-2English
Pagina's (van-tot)081402-1-081402-4
Aantal pagina's4
TijdschriftPhysical Review. B: Condensed Matter and Materials Physics
Nummer van het tijdschrift8
StatusPublished - feb-2009

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