Nonreciprocal surface acoustic wave propagation via magneto-rotation coupling
Open Access
- 7 August 2020
- journal article
- research article
- Published by American Association for the Advancement of Science (AAAS) in Science Advances
- Vol. 6 (32), eabb1724
- https://doi.org/10.1126/sciadv.abb1724
Abstract
A fundamental form of magnon-phonon interaction is an intrinsic property of magnetic materials, the “magnetoelastic coupling.” This form of interaction has been the basis for describing magnetostrictive materials and their applications, where strain induces changes of internal magnetic fields. Different from the magnetoelastic coupling, more than 40 years ago, it was proposed that surface acoustic waves may induce surface magnons via rotational motion of the lattice in anisotropic magnets. However, a signature of this magnon-phonon coupling mechanism, termed magneto-rotation coupling, has been elusive. Here, we report the first observation and theoretical framework of the magneto-rotation coupling in a perpendicularly anisotropic film Ta/CoFeB(1.6 nanometers)/MgO, which consequently induces nonreciprocal acoustic wave attenuation with an unprecedented ratio of up to 100% rectification at a theoretically predicted optimized condition. Our work not only experimentally demonstrates a fundamentally new path for investigating magnon-phonon coupling but also justifies the feasibility of the magneto-rotation coupling application.Keywords
Funding Information
- Japan Society for the Promotion of Science
- Japan Society for the Promotion of Science
- Japan Society for the Promotion of Science
- Japan Society for the Promotion of Science
- Swiss National Science Foundation
- Swiss National Science Foundation
- Japan Science and Technology Agency
- Japan Science and Technology Agency
- Ministry of Education, Science and Technology
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