论文标题
Moiré与Mott：一维双重晶格中的不通量和相互作用
Moiré versus Mott: Incommensuration and Interaction in One-Dimensional Bichromatic Lattices
论文作者
论文摘要
受扭曲的2D双层Moiré系统的丰富物理学的启发，我们研究了库仑相互作用的系统，这些系统通过精确的数值对角线化，受到两个重叠有限的一维晶格电位。无法匹配的基础晶格周期导致具有大型单位单元格的一维双分子“Moiré”超级晶格，因此具有强烈扁平的频带，指数呈指数增强，从而增强了无效的无尺寸电子 - 电子相互作用强度，并表现出在诊断填充物处增强的Mott Gaps的清晰签名。一个重要的非扰动发现是精确的晶格特征的显着微调效应，在与观察到的绝缘阶段的相对晶格期间的略有变化可能导致与观察到的扭曲倍层石化烯相关隔离相的脆弱性抑制相关的绝缘阶段。我们的预测应该在双分式光学晶格中直接验证，确定相互作用与不通量之间的竞争是Moiré超级晶格物理学的关键要素。
Inspired by the rich physics of twisted 2D bilayer moiré systems, we study Coulomb interacting systems subjected to two overlapping finite 1D lattice potentials of unequal periods through exact numerical diagonalization. Unmatching underlying lattice periods lead to a 1D bichromatic `moiré' superlattice with a large unit cell and consequently a strongly flattened band, exponentially enhancing the effective dimensionless electron-electron interaction strength and manifesting clear signatures of enhanced Mott gaps at discrete fillings. An important non-perturbative finding is a remarkable fine-tuning effect of the precise lattice commensuration, where slight variations in the relative lattice periods may lead to a suppression of the correlated insulating phase, in qualitative agreement with the observed fragility of the correlated insulating phase in twisted bilayer graphene. Our predictions, which should be directly verifiable in bichromatic optical lattices, establish that the competition between interaction and incommensuration is a key element of the physics of moiré superlattices.
