Absence of orbital current torque in Ta/ferromagnet bilayers.

ABSTRACT: It has become a heated debate as to whether the orbital Hall effect of a material could generate a non-local orbital current and a non-zero spin-orbit torque on an adjacent magnetic layer. Here, we report unambiguous evidence that, regardless of the ferromagnets (FMs) (e.g., Ni, Ni₈₁Fe₁₉, Fe, Fe₆₀Co₂₀B₂₀, and Fe₅₀Pt₅₀), the spin-orbit torque generated by an adjacent Ta, which is predicted to have a 50 times greater positive orbital Hall conductivity than the negative spin Hall conductivity, has essentially the same, negative efficiency. This agrees with the spin Hall effect of Ta being the only source of the interfacial torque. We identify that the constant, positive estimate of the torque of the Ta/FM samples fro

SUBMITTER: Liu Q 

PROVIDER: S-EPMC12485004 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature