Cai Li, Yu Chenglin, Zhao Wenxuan, Li Yong, Feng Hongmei, Zhou Heng-An, Wang Ledong, Zhang Xiaofang, Zhang Ying, Shi Youguo, Zhang Jinsong, Yang Lexian, Jiang Wanjun
State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China.
Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China.
Nano Lett. 2022 Sep 28;22(18):7441-7448. doi: 10.1021/acs.nanolett.2c02354. Epub 2022 Sep 13.
Rashba spin-orbit coupling (SOC) could facilitate an efficient interconversion between spin and charge currents. Among various systems, BiTeI holds one of the largest Rashba-type spin splittings. Unlike other Rashba systems (e.g., Bi/Ag and BiSe), an experimental investigation of the spin-to-charge interconversion in BiTeI remains to be explored. Through performing an angle-resolved photoemission spectroscopy (ARPES) measurement, such a large Rashba-type spin splitting with a Rashba parameter = 3.68 eV Å is directly identified. By studying the spin pumping effect in the BiTeI/NiFe bilayer, we reveal a very large inverse Rashba-Edelstein length ≈ 1.92 nm of BiTeI at room temperature. Furthermore, the monotonously increases to 5.00 nm at 60 K, indicating an enhanced Rashba SOC at low temperature. These results suggest that BiTeI films with the giant Rashba SOC are promising for achieving efficient spin-to-charge interconversion, which could be implemented for building low-power-consumption spin-orbitronic devices.
Rashba自旋轨道耦合（SOC）能够促进自旋电流与电荷电流之间的高效相互转换。在各种体系中，BiTeI具有最大的Rashba型自旋分裂之一。与其他Rashba体系（如Bi/Ag和BiSe）不同，BiTeI中自旋到电荷相互转换的实验研究仍有待探索。通过进行角分辨光电子能谱（ARPES）测量，直接确定了具有Rashba参数 = 3.68 eV Å的如此大的Rashba型自旋分裂。通过研究BiTeI/NiFe双层中的自旋泵浦效应，我们揭示了BiTeI在室温下非常大的逆Rashba-埃德尔斯坦长度≈1.92 nm。此外，在60 K时 单调增加到5.00 nm，表明在低温下Rashba SOC增强。这些结果表明，具有巨大Rashba SOC的BiTeI薄膜有望实现高效的自旋到电荷相互转换，这可用于构建低功耗自旋轨道电子器件。
