论文标题
Van der waals异质结构pt $ _ {2} $ hgse $ _ {3} $/cri $ _3 $用于拓扑valleytronics
Van der Waals Heterostructure Pt$_{2}$HgSe$_{3}$/CrI$_3$ for Topological Valleytronics
论文作者
论文摘要
我们在Van der Waals异质结构中确定了谷极化的Chern绝缘子，PT $ _ {2} $ HGSE $ _ {3} $/CRI $ _3 $，用于与电动，磁性，光学和机械效应之间相互作用的潜在应用。层间接近磁耦合几乎闭合了pt $ _ {2} $ hgse $ _ {3} $的频带间隙和强大的内部旋转旋转轨道耦合，进一步提高了Valley Demeneracy的100 MEV，导致了100 MEV，从而导致相反阀门的正和负带差距。在带有负间隙的山谷中，界面的Rashba自旋轨耦合耦合打开了17.8 MEV的拓扑带隙，通过添加$ H $ -bn层，该拓扑耦合将扩大到30.8 MEV。我们发现PT $ _ {2} $ HGSE $ _ {3} $ layer中的大轨道磁化比旋转大得多，这可以诱导可测量的光学KERR效应。山谷极化和Chern数与最近相邻CRI $ _3 $层的磁顺序耦合，在实验中，通过电气，磁性和机械手段可切换。 $ h $ bn的存在保护拓扑阶段，允许使用山谷，自旋和自由度层的超晶格构建。
We identify a valley-polarized Chern insulator in the van der Waals heterostructure, Pt$_{2}$HgSe$_{3}$/CrI$_3$, for potential applications with interplay between electric, magnetic, optical, and mechanical effects. The interlayer proximity magnetic coupling nearly closes the band gap of Pt$_{2}$HgSe$_{3}$ and the strong intra-layer spin-orbit coupling further lifts the valley degeneracy by over 100 meV leading to positive and negative band gaps at opposite valleys. In the valley with negative gap, the interfacial Rashba spin-orbit coupling opens a topological band gap of 17.8 meV, which is enlarged to 30.8 meV by adding an $h$-BN layer. We find large orbital magnetization in Pt$_{2}$HgSe$_{3}$ layer that is much larger than spin, which can induce measurable optical Kerr effect. The valley polarization and Chern number are coupled to the magnetic order of the nearest neighboring CrI$_3$ layer, which is switchable by electric, magnetic, and mechanical means in experiments. The presence of $h$-BN protects the topological phase allowing the construction of superlattices with valley, spin, and layer degrees of freedoms.
