2026-09-30 大阪大学
(左)圧電基板LiNbO3上に転写された層状物質と、表面弾性波を照射するための櫛型電極の概念図。(右) NbSe3における表面弾性波パワーで規格化した音響電流の試料温度依存性。140 K付近の電荷密度波転移温度で符号変化し、60 K以下の電荷密度波状態では音響電流が大きく増大している。
＜関連情報＞
- https://www.sci.osaka-u.ac.jp/ja/topics/17265/
- https://journals.aps.org/prb/abstract/10.1103/19zf-xskg
電荷密度波の遷移に伴う音響電気電流の著しい変調 Significant modulation of acoustoelectric current associated with charge density wave transitions
Natsumi Nikaido, Takuya Kawada, Koji Fujiwara, Jihoon Park, Nan Jiang, Kouta Kondou, Shintaro Takada, and Yasuhiro Niimi
Physical review B Published: 29 September, 2026
DOI: https://doi.org/10.1103/19zf-xskg
Abstract
We studied acoustoelectric (AE) currents in materials that undergo charge density wave (CDW) transitions, induced by a surface acoustic wave (SAW) on a piezoelectric substrate. The polarity and magnitude of the AE current in NbSe3 and 2−TaSe2 were modulated due to their CDW transitions. We also found that the sign of the AE current depends on the SAW propagation direction with respect to the crystalline axis of the substrate. A phenomenological model assuming strain-modified conductivity can qualitatively account for the significant modulation of the AE current associated with the CDW transition, as well as the SAW propagation orientation dependence. The present results offer a powerful probe for exploring SAW-electron interactions in van der Waals materials, thereby highlighting their potential for advancing the emerging field of straintronics.
