Identification of Orbital Pumping from Spin Pumping and Rectification Effects.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40857097.
- Also identified by DOI 10.1021/acs.nanolett.5c02641 and PMC identifier 12426985.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
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.