Nonreciprocal magnetoacoustic waves with out-of-plane phononic angular momenta.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38985868.
- Also identified by DOI 10.1126/sciadv.ado2504 and PMC identifier 11235162.
- 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
Surface acoustic wave (SAW) can carry phononic angular momentum, showing great potential as an energy-efficient way to control magnetism. Still, out-of-plane phononic angular momentum in SAW and its interaction with magnetism remain elusive. Here, we studied the SAW-induced magnetoacoustic waves and spin pumping in Ni-based films on LiNbO<sub>3</sub> with selected SAW propagation direction. The crystal inversion asymmetry induces circularly polarized phonons with large out-of-plane angular momenta so that up to 60% of the SAW power attenuates nonreciprocally controlled by the out-of-plane magnetization component. The SAW propagation direction dependence of the nonreciprocity verifies the crystal origin of the phononic angular momentum, and a chiral spin pumping demonstrates that the circular polarization can control the spin current generation efficiency. These results provide an additional degree of freedom for the acoustic control of magnetism and open an avenue for applying circularly polarized phonons.