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Spin torque, tunnel-current spin polarization and magnetoresistance in MgO magnetic tunnel junctions

G. D. Fuchs·J. A. Katine·S. I. Kiselev·D. Mauri·K. S. Wooley·D. C. Ralph·R. A. Buhrman
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Abstract

We examine the spin torque (ST) response of magnetic tunnel junctions (MTJs) with ultra-thin MgO tunnel barrier layers to investigate the relationship between the spin-transfer torque and the tunnel magnetoresistance (TMR) under finite bias. We find that the spin torque per unit current exerted on the free layer decreases by less than 10% over a bias range where the TMR decreases by over 40%. We examine the implications of this result for various spin-polarized tunneling models and find that it is consistent with magnetic-state-dependent effective tunnel decay lengths.

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G. D. Fuchs, J. A. Katine, S. I. Kiselev, D. Mauri, K. S. Wooley, D. C. Ralph, R. A. Buhrman. 2005-10-28. Spin torque, tunnel-current spin polarization and magnetoresistance in MgO magnetic tunnel junctions. https://doi.org/10.1103/physrevlett.96.186603

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