论文标题
扭曲的双层蜂窝量子磁铁中的木元带
Magnon bands in twisted bilayer honeycomb quantum magnets
论文作者
论文摘要
我们使用线性自旋波理论研究了扭曲的双层蜂窝量子磁铁的木核带。尽管层间耦合可以是铁磁或抗铁磁磁性，但我们将内部磁磁性保持一只铁磁剂，以避免可能的挫败感。对于层间铁磁案例，我们发现镁带与相应的电子能谱具有相似的特征。尽管狄拉克点附近的线性分散体保存在扭曲的双层磁体的木元带中，但随着扭角的减小，它们的斜率逐渐减小。另一方面，层间抗铁磁耦合会产生完全不同的磁谱。由于两层旋转的相反方向，通常将两个单层木片光谱未耦合。我们还为非常小的扭曲角度开发了低能的连续理论，该理论已经过验证，可与精确的紧密结合计算相吻合。由于二维磁性材料的快速发展，我们的结果可能会在实验上观察到。
We study the magnon bands of twisted bilayer honeycomb quantum magnets using linear spin wave theory. Although the interlayer coupling can be ferromagnetic or antiferromagnetic, we keep the intralayer one ferromagnetic to avoid possible frustration. For the interlayer ferromagnetic case, we find the magnon bands have similar features with the corresponding electronic energy spectrums. Although the linear dispersions near the Dirac points are preserved in the magnon bands of twisted bilayer magnets, their slopes are graduately reduced with the decrease of the twist angles. On the other hand, the interlayer antiferromagnetic couplings generate quite different magnon spectra. The two single-layered magnon spectra are usually undecoupled due to the opposite orientations of the spins in the two layers. We also develop a low-energy continuous theory for very small twist angles, which has been verified to fit well with the exact tight-binding calculations. Our results may be experimentally observed due to the rapid progress in two-dimensional magnetic materials.
