Xiao Feiping, Tong Qingjun
School of Physics and Electronics, Hunan University, Changsha 410082, People's Republic of China.
Nano Lett. 2022 May 25;22(10):3946-3952. doi: 10.1021/acs.nanolett.2c00401. Epub 2022 May 12.
We show that the anisotropic energy of a 2D antiferromagnet is greatly enhanced via stacking on a magnetic substrate layer, arising from the sublattice-dependent interlayer magnetic interaction that defines an effective anisotropic energy. Interestingly, this effective energy couples strongly with the interlayer stacking order and the magnetic order of the substrate layer, providing unique mechanical and magnetic means to control the antiferromagnetic order. These two types of control methods distinctly affect the sublattice magnetization dynamics, with a change in the ratio of sublattice precession amplitudes in the former and its chirality in the latter. In moiré superlattices formed by a relative twist or strain between the layers, the coupling with stacking order introduces a landscape of effective anisotropic energy across the moiré, which can be utilized to create nonuniform antiferromagnetic textures featuring periodically localized low-energy magnons.
我们表明，二维反铁磁体的各向异性能通过堆叠在磁性衬底层上而大大增强，这源于依赖于亚晶格的层间磁相互作用，该相互作用定义了有效各向异性能。有趣的是，这种有效能量与层间堆叠顺序和衬底层的磁序强烈耦合，提供了控制反铁磁序的独特机械和磁性手段。这两种控制方法对亚晶格磁化动力学有明显影响，前者会改变亚晶格进动幅度的比例，后者会改变其手性。在由层间相对扭曲或应变形成的莫尔超晶格中，与堆叠顺序的耦合在莫尔区域引入了有效各向异性能景观，可用于创建具有周期性局域化低能磁振子的非均匀反铁磁纹理。
