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arXiv · 2101.10521

Lack of simple correlation between switching current density and spin-orbit torque efficiency of perpendicularly magnetized spin-current generator/ferromagnet heterostructures

Lijun Zhu·D. C. Ralph·R. A. Buhrman
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Abstract

Spin-orbit torque can drive electrical switching of magnetic layers. Here, we report that at least for micrometer-sized samples there is no simple correlation between the efficiency of dampinglike spin-orbit torque (ξ_DL^j) and the critical switching current density of perpendicularly magnetized spin-current generator/ferromagnet heterostructures. We find that the values of ξ_DL^j based on switching current densities can either under- or over-estimated ξ_DL^j by up to tens of times in a domain-wall depinning analysis, while in the macrospin analysis based on the switching current density ξ_DL^j can be overestimated by up to thousands of times. When comparing the relative strengths of ξ_DL^j of spin-current generators, the critical switching current densities by themselves are a poor predictor.

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Lijun Zhu, D. C. Ralph, R. A. Buhrman. 2021-01-26. Lack of simple correlation between switching current density and spin-orbit torque efficiency of perpendicularly magnetized spin-current generator/ferromagnet heterostructures. https://doi.org/10.1103/physrevapplied.15.024059

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