Acoustic spin rotation in heavy-metal-ferromagnet bilayers

Yang Cao; Hao Ding; Yalu Zuo; Xiling Li; Yibing Zhao; Tong Li; Na Lei; Jiangwei Cao; Mingsu Si; Li Xi; Chenglong Jia; Desheng Xue; Dezheng Yang

doi:10.1038/s41467-024-45317-9

Acoustic spin rotation in heavy-metal-ferromagnet bilayers

Nat Commun. 2024 Feb 3;15(1):1013. doi: 10.1038/s41467-024-45317-9.

Authors

Yang Cao¹, Hao Ding¹, Yalu Zuo¹, Xiling Li¹, Yibing Zhao¹, Tong Li¹, Na Lei², Jiangwei Cao¹, Mingsu Si¹, Li Xi¹, Chenglong Jia¹, Desheng Xue³, Dezheng Yang⁴

Affiliations

¹ Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China.
² Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
³ Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China. xueds@lzu.edu.cn.
⁴ Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou, 730000, China. yangdzh@lzu.edu.cn.

Abstract

Through pumping a spin current from ferromagnet into heavy metal (HM) via magnetization precession, parts of the injected spins are in-plane rotated by the lattice vibration, namely acoustic spin rotation (ASR), which manifests itself as an inverse spin Hall voltage in HM with an additional 90° difference in angular dependency. When reversing the stacking order of bilayer with a counter-propagating spin current or using HMs with an opposite spin Hall angle, such ASR voltage shows the same sign, strongly suggesting that ASR changes the rotation direction due to interface spin-orbit interaction. With the drift-diffusion model of spin transport, we quantify the efficiency of ASR up to 30%. The finding of ASR endows the acoustic device with an ability to manipulate spin, and further reveals a new spin-orbit coupling between spin current and lattice vibration.