论文标题
在二维SI $ _2 $ bi $ _2 $中揭示巨型隐藏Rashba效果
Unveiling Giant Hidden Rashba Effects in Two-Dimensional Si$_2$Bi$_2$
论文作者
论文摘要
最近，众所周知，二维材料中隐藏的Rashba（R-2）效应引起了一种新型的物理现象，称为旋转层锁定（SLL）。但是，不仅尚不清楚其潜在的基本机制，而且只有少数材料表现出较弱的SLL。在这里，通过第一原理密度的功能理论和模型汉密尔顿计算，我们揭示了R-2 SLL可以取决于Sublayer-Sublayer相互作用与自旋轨道耦合（SOC）之间的竞争，这与RashBA强度有关。另外，轨道角动量分布是实现强R-2 SLL的另一个关键点。我们建议一种新颖的2D材料Si $ _2 $ bi $ _2 $对于强R-2 SLL具有理想状态，其RashBA强度评估为2.16eVå，这是我们所知的2D R-2材料中有史以来最大的价值。此外，我们揭示了双层结构中的层间相互作用确保R-2状态在空间上距离较远，这意味着潜在的旋转型应用。
Recently, it has been known that the hidden Rashba (R-2) effect in two-dimensional materials gives rise to a novel physical phenomenon called spin-layer locking (SLL). However, not only has its underlying fundamental mechanism been unclear, but also there are only a few materials exhibiting weak SLL. Here, through the first-principles density functional theory and model Hamiltonian calculation, we reveal that the R-2 SLL can be determined by the competition between the sublayer-sublayer interaction and the spin-orbit coupling (SOC), which is related to the Rashba strength. In addition, the orbital angular momentum distribution is another crucial point to realize the strong R-2 SLL. We propose that a novel 2D material Si$_2$Bi$_2$ possesses an ideal condition for the strong R-2 SLL, whose Rashba strength is evaluated to be 2.16 eVÅ, which is the greatest value ever observed in 2D R-2 materials to the best of our knowledge. Furthermore, we reveal that the interlayer interaction in a bilayer structure ensures R-2 states spatially farther apart, implying a potential application in spintronics.
