论文标题
在双层石墨烯中分层的Rashba自旋轨道耦合：旋转手性的丧失，对称性断裂和拓扑过渡
Layered Opposite Rashba Spin-Orbit Coupling in Bilayer Graphene: Loss of Spin Chirality, Symmetry Breaking and Topological Transition
论文作者
论文摘要
双层石墨烯中的反转对称性允许对相反的Rashba自旋轨道耦合（LO-RSOC） - RSOC具有相同幅度但相反的符号的情况，在两个耦合的空间分离层中。我们表明，与公共均匀的RSOC相比，LO-RSOC导致动量空间中自旋手性的丧失。这种手性损失使得难以实验确定LO-RSOC（以10 MeV的比例）是否存在，因为频带结构对其不敏感。为了解决这个问题，我们建议通过门控打破反转对称性或磁场来识别LO-RSOC，以打破时间反转对称性。值得注意的是，随着系统与Lo Rashba州的偏离，我们观察到琐碎和非平凡的带拓扑之间的过渡。 AB Inito计算表明，由AU的两个单层封装的双层石墨烯是候选人成为Lo Rashba系统的候选者。
Inversion symmetry in bilayer graphene allows for layered opposite Rashba spin-orbit coupling (LO-RSOC) -- the situation when the RSOC has the same magnitude but the opposite sign in two coupled spatially separated layers. We show that the LO-RSOC results in the loss of spin chirality in the momentum space, in contrast to the common uniform RSOC. This chirality loss makes it difficult to experimentally establish whether the LO-RSOC (on the scale of 10 meV) exists, because the band structure is insensitive to it. To solve this problem, we propose to identify the LO-RSOC either by gating to break the inversion symmetry or by magnetic field to break the time-reversal symmetry. Remarkably, we observe the transition between trivial and non-trivial band topology as the system deviates from the LO Rashba state. Ab inito calculations suggest that bilayer graphene encapsulated by two monolayers of Au is a candidate to be a LO Rashba system.
