Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China.
International Quantum Academy, Shenzhen 518048, China.
Phys Rev Lett. 2023 Mar 3;130(9):096701. doi: 10.1103/PhysRevLett.130.096701.
We report on coherent propagation of antiferromagnetic (AFM) spin waves over a long distance (∼10 μm) at room temperature in a canted AFM α-Fe_{2}O_{3} owing to the Dzyaloshinskii-Moriya interaction (DMI). Unprecedented high group velocities (up to 22.5 km/s) are characterized by microwave transmission using all-electrical spin wave spectroscopy. We derive analytically AFM spin-wave dispersion in the presence of the DMI which accounts for our experimental results. The AFM spin waves excited by nanometric coplanar waveguides have large wave vectors in the exchange regime and follow a quasilinear dispersion relation. Fitting of experimental data with our theoretical model yields an AFM exchange stiffness length of 1.7 Å. Our results provide key insights on AFM spin dynamics and demonstrate high-speed functionality for AFM magnonics.
我们报道了反铁磁（AFM）自旋波在室温下在倾斜 AFM α-Fe_2O_3 中相干传播的现象，其传播距离长达 10μm，这归因于 Dzyaloshinskii-Moriya 相互作用（DMI）。通过全电自旋波谱学，我们使用微波传输技术，首次表征了高达 22.5km/s 的超高群速度。我们从理论上推导出了存在 DMI 时 AFM 自旋波的色散关系，这与我们的实验结果相符。由纳米共面波导激发的 AFM 自旋波在交换区域具有较大的波矢，并遵循准线性色散关系。通过将实验数据与我们的理论模型拟合，我们得到了 AFM 交换弹性长度为 1.7Å。我们的研究结果提供了对 AFM 自旋动力学的重要见解，并展示了 AFM 磁振子的高速功能。
