Identification of Orbital Pumping from Spin Pumping and Rectification Effects
The recently predicted mechanism of orbital pumping can enable the generation of pure orbital current from a precessing ferromagnet (FM) without the need for electrical current injection. This orbital current can be efficiently injected into an adjacent nonmagnetic material (NM) without being hampered by electrical conductivity mismatch. However, experimentally identifying this novel effect presents significant challenges due to the substantial background contributions from spin pumping and spin rectification effects (SREs). In this work, we disentangle the effects of orbital pumping from spin pumping in bilayer structures composed of Nb/Ni and Nb/Fe<sub>60</sub>Co<sub>20</sub>B<sub>20</sub> by observing a sign reversal of the measured voltage. This reversal arises from the competing signs of the spin and orbital Hall effects in the Nb. We establish methods to differentiate the pumping signal from SREs by analyzing the distinct angular dependence of the measured voltage and its spatial dependence relative to the radio frequency excitation source.
Authors
- G. Jakob (ORCID: https://orcid.org/0000-0001-9466-0840)
- Sachin Krishnia (ORCID: https://orcid.org/0000-0002-2710-8244)
- Rahul Gupta (ORCID: https://orcid.org/0000-0001-6523-3161)
- Kazuya Ando (ORCID: https://orcid.org/0000-0002-1535-9417)
- Fabian Kammerbauer (ORCID: https://orcid.org/0000-0002-5762-2762)
- Nancy P. Keller (ORCID: https://orcid.org/0000-0002-4386-9473)
- Mathias Kläui (ORCID: https://orcid.org/0000-0002-4848-2569)
- Arnab Bose (ORCID: https://orcid.org/0000-0003-4696-3112)
- Hiroki Hayashi (ORCID: https://orcid.org/0009-0006-5465-786X)
- Nozomi Soya
- Elias Hauth
- Hisanobu Kashiki
Institutions
- University of Applied Sciences Mainz (DE)
- Johannes Gutenberg University Mainz (DE)
- Keio University (JP)
- Norwegian University of Science and Technology (NO)
- Lapland University of Applied Sciences (FI)
- Spintronics Research Network of Japan (JP)
- Indian Institute of Technology Kanpur (IN)
Publication Details
- Journal
- Nano Letters
- Published
- 2025-08-26
- DOI
- https://doi.org/10.1021/acs.nanolett.5c02641
- Citations
- 3
- Primary Topic
- Characterization and Applications of Magnetic Nanoparticles
- Type
- article
- Field-Weighted Citation Impact
- 2.02
Funders
- Alexander von Humboldt-Stiftung
- Deutsche Forschungsgemeinschaft
- Ministry of Education, Culture, Sports, Science and Technology
- Norges Forskningsråd
- Japan Society for the Promotion of Science
- Science and Engineering Research Board
- H2020 European Research Council
- H2020 Future and Emerging Technologies
- HORIZON EUROPE European Innovation Council