论文标题
与HBN对齐的ABC石墨烯三层元素中的Mott相关性
Mott correlations in ABC graphene trilayer aligned with hBN
论文作者
论文摘要
在某些石墨烯异质结构中发现的相关阶段的性质正在争论中。我们使用动力学平均场理论（DMFT）来分析接近半填充对此类系统之一的局部相关性的影响，ABC Trilayer石墨烯与六角形硝化氢（ABC/HBN）对齐，该系统呈现MoiréSuperlattice。该系统显示在Moiré晶格的整数填充物处的绝缘阶段，正是填充物具有足够强的库仑相互作用（u $ _ {\ rm mott} $），可能会产生金属隔离剂Mott Transition。我们的计算表明，在与预期在实验中相关的大小相互作用时，电子状态受到明显的光谱重量转移的强烈影响。这种效果在相互作用大于u $ _ {\ rm mott} $的相互作用中出现，并且不需要对称性破坏，它会影响在磁性转变上方的温度下产生异常温度和掺杂依赖性的电子特性，而不存在与HBN相关的情况。接近莫特（Mott）的过渡，我们发现现场相互作用促进了一种抗铁磁（AF）状态，可能打破了c $ _3 $对称性，它将与来自现场交换相互作用引起的铁磁性竞争以确定地面状态。
The nature of the correlated phases found in some graphene heterostructures is under debate. We use dynamical mean-field theory (DMFT) to analyze the effect of local correlations close to half-filling on one of such systems, the ABC trilayer graphene aligned with hexagonal boron nitride (ABC/hBN), which presents a moiré superlattice. This system has shown insulating phases at integer fillings of the moiré lattice, precisely the fillings at which a sufficiently strong Coulomb interaction (U$_{\rm Mott}$) may produce a metal-insulator Mott transition. Our calculations show that the electronic states are strongly affected by a significant spectral weight transfer at interactions with magnitudes expected to be relevant in experiments. This effect, which emerges at interactions considerably smaller than U$_{\rm Mott}$ and does not require symmetry breaking, impacts the electronic properties at temperatures above the magnetic transitions producing anomalous temperature and doping dependences not present without alignment to hBN. Close to the Mott transition we find that onsite interactions promote an antiferromagnetic (AF) state, probably breaking the C$_3$ symmetry, that will compete with the ferromagnetism arising from intersite exchange interactions to determine the ground state.
