Description of current-driven torques in magnetic tunnel junctions

Aurélien Manchon (1) , Natalya Ryzhanova (1, 2) , A. Vedyayev (1, 3) , Mairbek Chschiev (4) , Bernard Dieny (1)

1 SPINTEC - SPINtronique et TEchnologie des Composants
2 Department of Physics
3 Department of Physics
4 MINT Center

A free electron description of spin-dependent tranport in magnetic tunnel junctions with non collinear magnetizations is presented. We investigate the origin of transverse spin density in tunnelling transport and the quantum interferences which give rise to oscillatory torques on the local magnetization. Spin transfer torque is also analyzed and an important bias asymmetry is found as well as a damped oscillatory behaviour. Furthermore, we investigate the influence of the s-d exchange coupling on torque in particular in the case of half-metallic MTJ in which the spin transfer torque is due to interfacial spin-dependent reflections.

Mots clés: Spintronics; Tunnel Magnetoresistance; Magnetic Tunnel Junction; Spin Transfer Torque

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Aurélien Manchon, Natalya Ryzhanova, A. Vedyayev, Mairbek Chschiev, Bernard Dieny. Description of current-driven torques in magnetic tunnel junctions. 2007. ⟨hal-00193154⟩