Wu Jiangbin, Yao Yu, Lin Miao-Ling, Rösner Malte, Du Zhonghao, Watanabe Kenji, Taniguchi Takashi, Tan Ping-Heng, Haas Stephan, Wang Han
Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, 90089, USA.
Department of Physics & Astronomy, University of Southern California, Los Angeles, CA, 90089, USA.
Adv Mater. 2022 May;34(20):e2108506. doi: 10.1002/adma.202108506. Epub 2022 Apr 14.
Novel 2D magnets exhibit intrinsic electrically tunable magnetism down to the monolayer limit, which has significant value for nonvolatile memory and emerging computing device applications. In these compounds, spin-phonon coupling (SPC) typically plays a crucial role in magnetic fluctuations, magnon dissipation, and ultimately establishing long-range ferromagnetic order. However, a systematic understanding of SPC in 2D magnets that combines theory and experiment is still lacking. In this work, monolayer chromium tribromide is studied to investigate SPC in 2D magnets via Raman spectroscopy and first principle calculations. The experimental Curie temperature and phonon shifts are found to be in good agreement with the numerical simulations. Specifically, it is demonstrated how magnetic exchange interactions affect phonon vibrations, which helps establish design fundamentals for 2D magnetic materials and other related devices.
新型二维磁体在单层极限下仍表现出本征电可调磁性，这对于非易失性存储器和新兴计算设备应用具有重要价值。在这些化合物中，自旋 - 声子耦合（SPC）通常在磁涨落、磁振子耗散以及最终建立长程铁磁序方面起着关键作用。然而，目前仍缺乏对二维磁体中SPC的系统理解，这种理解需要结合理论和实验。在这项工作中，通过拉曼光谱和第一性原理计算对单层三溴化铬进行研究，以探究二维磁体中的SPC。实验测得的居里温度和声子位移与数值模拟结果吻合良好。具体而言，展示了磁交换相互作用如何影响声子振动，这有助于为二维磁性材料和其他相关器件建立设计基础。
