Spin-orbit torques originating from bulk and interface in Pt-based structures
| Autor: | Hiroki Hayashi, Kazuya Ando, Hiroto Sakimura, Akira Musha |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Physics
Condensed Matter - Materials Science Condensed matter physics Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Heterojunction Applied Physics (physics.app-ph) Physics - Applied Physics Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter::Materials Science Ferromagnetism Torque Condensed Matter::Strongly Correlated Electrons Astrophysics::Earth and Planetary Astrophysics Orbit (control theory) Spin (physics) |
| Popis: | We investigated spin-orbit torques in prototypical Pt-based spintronic devices. We found that, in Pt/Ni and Pt/Fe bilayers, the damping-like torque efficiency depends on the thickness of the Pt layer. We also found that the damping-like torque efficiency is almost identical in the Pt/Ni and Pt/Fe bilayers despite the stronger spin memory loss at the Pt/Fe interface. These results suggest that although the dominant source of the damping-like torque is the bulk spin Hall effect in the Pt layer, a sizable damping-like torque is generated by the interface in the Pt/Fe bilayer due to the stronger interfacial spin-orbit coupling. In contrast to the damping-like torque, whose magnitude and sign are almost identical in the Pt/Ni and Pt/Fe bilayers, the field-like torque strongly depends on the choice of the ferromagnetic layer. The sign of the field-like torque originating from the bulk spin Hall effect in the Pt layer is opposite between the Pt/Ni and Pt/Fe bilayers, which can be attributed to the opposite sign of the imaginary part of the spin-mixing conductance. These results demonstrate that the spin-orbit torques are quite sensitive to the electronic structure of the FM layer. The analysis has been revised based on the ST-FMR signals at higher frequencies |
| Databáze: | OpenAIRE |
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