Journal Article

Electrical detection of spin pumping in van der Waals ferromagnetic Cr2Ge2Te6 with low magnetic damping

Yu, Guoqiang, Zhang, Yu, Zhu, Mingliang, Shao, Qiming, Xu, Hongjun, Wang, Shouguo, Cheng, Chen, Shi, Youguo, Gu, Lin, Wei, Hongxiang, He, Congli, Huang, Yuan, Lan, Guibin, Zhang, Guangyu, Zhang, Qinghua, Coey, Michael, Feng, Jiafeng, Wan, Caihua, He, Wenqing, Han, Xiufeng, Jia, Ke, Yuan, Zhe, Dong, Jing, Wei, Jinwu, Meng, Fanqi

2023

Overview

The discovery of magnetic order in atomically-thin van der Waals materials has strengthened the alliance between spintronics and two-dimensional materials. An important use of magnetic two-dimensional materials in spintronic devices, which has not yet been demonstrated, would be for coherent spin injection via the spin-pumping effect. Here, we report spin pumping from Cr 2 Ge 2 Te 6 into Pt or W and detection of the spin current by inverse spin Hall effect. The magnetization dynamics of the hybrid Cr 2 Ge 2 Te 6 /Pt system are measured, and a magnetic damping constant of ~ 4–10 × 10 −4 is obtained for thick Cr 2 Ge 2 Te 6 flakes, a record low for ferromagnetic van der Waals materials. Moreover, a high interface spin transmission efficiency (a spin mixing conductance of 2.4 × 10 19 /m 2 ) is directly extracted, which is instrumental in delivering spin-related quantities such as spin angular momentum and spin-orbit torque across an interface of the van der Waals system. The low magnetic damping that promotes efficient spin current generation together with high interfacial spin transmission efficiency suggests promising applications for integrating Cr 2 Ge 2 Te 6 into low-temperature two-dimensional spintronic devices as the source of coherent spin or magnon current. Spin-pumping experimental technique where a DC or AC spin current is generated, and typically transferred to a heavy metal layer where it can be detected via electrical measurements. While well established in conventional materials, coherent spin-pumping in van der Waals magnetic materials is challenging due to the low damping and high-quality interface requirements. Here, Xu et al demonstrate coherent spin pumping in the van der Waals magnet Cr2Ge2Te6.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 639/766/119/1001 / 639/766/119/997 / Alternating current / Angular momentum / Coherence / Electrical measurement / Electrons / Ferromagnetic materials / Hall effect / Heavy metals / Humanities and Social Sciences / Hybrid systems / Low temperature / Magnetic damping / Magnetic materials / Magnons / multidisciplinary / Pumping / Science / Science (multidisciplinary) / Spin dynamics / Spintronics / Transmission efficiency / Two dimensional materials