论文标题
扭曲双层石墨烯的低能模型的阻塞和干扰
Obstruction and Interference in Low Energy Models for Twisted Bilayer Graphene
论文作者
论文摘要
带有大周期Moiré超晶格裂缝的扭曲双层石墨烯（TBLG）的电子带形成狭窄的Bloch迷你班，这些小型小班级通过远程分散带的禁用能量差异在光谱中分离出来。当这些差距足够大时，可以研究正确代表小型动力学的带射击的哈密顿量。这不可避免地引入了由假定的投影形式产生的非平凡的几何约束。在这里，我们表明，这种选择在低能实验性观察的签名中具有深远的影响，因此可以用来严格限制适当的低能理论的分析形式。我们发现，可以通过仔细分析来自Moiré超级突变性尺度上的杂质潜在的Bloch波的反向散射产生的电子密度来实现。我们提供了可以指导实验工作以清楚区分低能带结构的竞争模型的效果的数值估计值。
The electronic bands of twisted bilayer graphene (TBLG) with a large-period moiré superlattice fracture to form narrow Bloch minibands that are spectrally isolated by forbidden energy gaps from remote dispersive bands. When these gaps are sufficiently large, one can study a band-projected Hamiltonian that correctly represents the dynamics within the minibands. This inevitably introduces nontrivial geometrical constraints that arise from the assumed form of the projection. Here we show that this choice has a profound consequence in a low-energy experimentally-observable signature which therefore can be used to tightly constrain the analytic form of the appropriate low-energy theory. We find that this can be accomplished by a careful analysis of the electron density produced by backscattering of Bloch waves from an impurity potential localized on the moiré superlattice scale. We provide numerical estimates of the effect that can guide experimental work to clearly discriminate between competing models for the low-energy band structure.
