2020/05/28
Keio University
Japan Science and Technology Agency (JST)
Yuki Kurimune (then a second-year master's student) of the Graduate School of Science and Technology at Keio University, Professor Yukio Nozaki of the Faculty of Science and Technology, and Associate Professor Mamoru Matsuo of the Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, have discovered that injecting sound waves into a magnet generates magnetic waves called "spin waves" due to the magneto-rotation effect.
The magneto-rotation effect is a historically significant phenomenon that demonstrates that the origin of magnetism in materials is the rotational motion of electrons. However, its effect is very small, and its application to spintronic devices, which require magnetic control of materials, was considered impossible.
This research group fabricated a thin-film nickel-iron alloy magnet with a thickness of 20 nanometers and discovered that by injecting sound waves that rotate crystal lattice points more than one billion times per second while propagating on the solid surface, spin waves originating from the magneto-rotation effect are generated.
This research is the first in the world to demonstrate that sound waves can produce a giant magneto-rotation effect, and it is expected to significantly pave the way for the application of the magneto-rotation effect to spintronic devices, which was previously impossible.
The results of this research were published in the online edition of the American Physical Society journal "Physical Review Letters" on May 27, 2020 (U.S. Eastern Time).
Please see below for the full press release.