论文标题
激子Chern绝缘子和动力学的铁磁学$ _2 $/WSE $ _2 $MoiréBiLayer
Excitonic Chern insulator and kinetic ferromagnetism in MoTe$_2$/WSe$_2$ moiré bilayer
论文作者
论文摘要
我们为AB堆叠的Mote $ _2 $/WSE $ _2 $系统提出了一种新的量子异常霍尔（QAH）效果的新机制。基于AB堆叠中抑制层间隧道的观察结果，我们考虑了一个模型，其两层通过库仑相互作用耦合。两层的Moiré晶格被转移，一起形成一个蜂窝状晶格。最初，该系统位于$ν_t= 1 $的层偏振莫特绝缘子中。但是，在位移场的情况下，分别将相等数量的孔和电子掺杂到两层中，并形成层间激子冷凝。通过平均字段理论，我们在某个参数制度中找到了p $ \ pm $ ip IP激烈的凝结，这导致Chern绝缘子具有Chern Number $ C = \ pm 1 $。由于动能而不是相互作用，山谷是极化的。但是，根据远离对称点的小扰动，这两层的极化可以是相同的或相反的。结果，山谷两极化和瓦利相干（IVC）Chern绝缘子相是可能的。后者在两层中具有相同的旋转$ s_z $。
We propose a new mechanism for quantum anomalous Hall (QAH) effect in the AB stacked MoTe$_2$/WSe$_2$ system. Based on the observation that the inter-layer tunneling is suppressed in the AB stacking, we consider a model with two layers coupled through the Coulomb interaction. The moiré lattices of the two layers are shifted to form a honeycomb lattice together. Initially, the system is in a layer-polarized Mott insulator at $ν_T=1$. But with a displacement field, an equal number of holes and electrons are doped into the two layers respectively and they form inter-layer exciton condensation. Through mean field theory, we find p$\pm$ip exciton condensation in a certain parameter regime, which leads to a Chern insulator with Chern number $C=\pm 1$. The valleys are polarized due to the kinetic energy instead of interaction. But the polarization in the two layers can be either the same or opposite depending on small perturbations away from a symmetric point. As a result, both valley polarized and inter-valley coherent (IVC) Chern insulator phases are possible. The latter has the same spin $S_z$ in the two layers.
