论文标题
单层和双层铬的旋转和旋转耦合
Superexchange and spin-orbit coupling in monolayer and bilayer chromium trihalides
论文作者
论文摘要
我们构建了一个微观模型，以研究由于Trihalides铬的电子跳跃而导致的层间和间层次数（$ \ MATHRM {CRX} _3 $，X = CL，BR和I）。在评估superexchange时，我们确定了跳跃中相关的中间激励。在我们的研究中，我们发现X离子上$ p $ - 欧洲的中间孔对激发在介导各种类型的交换相互作用方面起着至关重要的作用。特别是，层间抗铁磁交换可以通过孔对介导的superexchange实现。有趣的是，我们还发现，这些虚拟跳跃过程相互竞争，导致较弱的层内铁磁交换。此外，我们还研究了对甲基汇合的自旋轨道耦合效应，并研究了dzyaloshinskii-moriya相互作用。最后，我们从密度功能理论中提取微观模型参数，以分析单层$ \ mathrm {cri} _3 $中的交换相互作用。
We build a microscopic model to study the intra- and inter-layer superexchange due to electrons hopping in chromium trihalides ($\mathrm{CrX}_3$, X= Cl, Br, and I). In evaluating the superexchange, we identify the relevant intermediate excitations in the hopping. In our study, we find that the intermediate hole-pairs excitations in the $p$-orbitals on X ion play a crucial role in mediating various types of exchange interactions. In particular, the inter-layer antiferromagnetic exchange may be realized by the hole-pair-mediated superexchange. Interestingly, we also find that these virtual hopping processes compete with each other leading to weak intra-layer ferromagnetic exchange. In addition, we also study the spin-orbit coupling effects on the superexchange and investigate the Dzyaloshinskii-Moriya interaction. Finally, we extract the microscopic model parameters from density functional theory for analyzing the exchange interactions in a monolayer $\mathrm{CrI}_3$.
