التفاصيل البيبلوغرافية
| العنوان: |
Transition of laser-induced terahertz spin currents from torque- to conduction-electron-mediated transport |
| المؤلفون: |
Jiménez-Cavero, P., Gückstock, O., Nadvornik, L., Lucas, I., Seifert, T., Wolf, M., Rouzegar, R., Brouwer, P., Becker, S., Jakob, G., Kläui, M., Guo, C., Wan, C., Han, X., Jin, Z., Zhao, H., Wu, D., Morellón, L., Kampfrath, T. |
| المصدر: |
Physical Review B |
| سنة النشر: |
2022 |
| مصطلحات موضوعية: |
geo, manag |
| الوصف: |
Spin transport is crucial for future spintronic devices operating at bandwidths up to the terahertz range. In F|N thin-film stacks made of a ferromagnetic/ferrimagnetic layer F and a normal-metal layer N, spin transport is mediated by (1) spin-polarized conduction electrons and/or (2) torque between electron spins. To identify a crossover from (1) to (2), we study laser-driven spin currents in F|Pt stacks where F consists of model materials with different degrees of electrical conductivity. For the magnetic insulators yttrium iron garnet, gadolinium iron garnet (GIG) and γ−Fe 2 O 3 , identical dynamics is observed. It arises from the terahertz interfacial spin Seebeck effect (SSE), is fully determined by the relaxation of the electrons in the metal layer, and provides a rough estimate of the spin-mixing conductance of the GIG/Pt and γ−Fe 2 O 3 /Pt interfaces. Remarkably, in the half-metallic ferrimagnet Fe 3 O 4 (magnetite), our measurements reveal two spin-current components with opposite direction. The slower, positive component exhibits SSE dynamics and is assigned to torque-type magnon excitation of the A- and B-spin sublattices of Fe 3 O 4 . The faster, negative component arises from the pyrospintronic effect and can consistently be assigned to ultrafast demagnetization of minority-spin hopping electrons. This observation supports the magneto-electronic model of Fe 3 O 4 . In general, our results provide a route to the contact-free separation of torque- and conduction-electron-mediated spin currents. |
| نوع الوثيقة: |
article in journal/newspaper |
| اللغة: |
English |
| العلاقة: |
http://hdl.handle.net/21.11116/0000-000A-7D81-8Test |
| الإتاحة: |
http://hdl.handle.net/21.11116/0000-000A-7D81-8Test |
| حقوق: |
undefined |
| رقم الانضمام: |
edsbas.4488F622 |
| قاعدة البيانات: |
BASE |
