Quantification of the spin-Hall anti-damping torque with a resonance spectrometer

Satoru Emori; Tianxiang Nan; Trevor M. Oxholm; Carl T. Boone; John G. Jones; Brandon M. Howe; Gail J. Brown; David E. Budil; Nian X. Sun

doi:10.1063/1.4906062

arXiv · 1411.6166

Quantification of the spin-Hall anti-damping torque with a resonance spectrometer

Satoru Emori·Tianxiang Nan·Trevor M. Oxholm·Carl T. Boone·John G. Jones·Brandon M. Howe·Gail J. Brown·David E. Budil·Nian X. Sun

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Abstract

We present a simple technique using a cavity-based resonance spectrometer to quantify the anti-damping torque due to the spin Hall effect. Modification of ferromagnetic resonance is observed as a function of small DC current in sub-mm-wide strips of bilayers, consisting of magnetically soft FeGaB and strong spin-Hall metal Ta. From the detected current-induced linewidth change, we obtain an effective spin Hall angle of 0.08-0.09 independent of the magnetic layer thickness. Our results demonstrate that a sensitive resonance spectrometer can be a general tool to investigate spin Hall effects in various material systems, even those with vanishingly low conductivity and magnetoresistance.

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Satoru Emori, Tianxiang Nan, Trevor M. Oxholm, Carl T. Boone, John G. Jones, Brandon M. Howe, Gail J. Brown, David E. Budil, Nian X. Sun. 2014-11-22. Quantification of the spin-Hall anti-damping torque with a resonance spectrometer. https://doi.org/10.1063/1.4906062

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