论文标题
两腿梯子模型中的准灯波带物理及其与魔法扭曲的双层石墨烯的关系
Quasi-flat-band physics in a two-leg ladder model and its relation to magic-angle twisted bilayer graphene
论文作者
论文摘要
我们研究了由通量螺纹的两腿阶梯模型的单粒子特性，其腿与空间变化的期限结合。尽管先验与扭曲的双层石墨烯（TBG）无关，但发现该模型具有引人注目的相似性：准纯灯光低能带的特征与魔法角度TBG相似。我们使用密度基质重新归一化组在模型中研究了颗粒间相互作用的影响，并发现当频带是准灯时，基态是铁电磁莫特绝缘子。随着频带变得更加分散，该系统会经历铁磁到抗铁磁转变。我们讨论我们的模型不仅与TBG中的魔法物理学相关，还与一维相关性和磁性的更大背景相关。
We study the single- and many-particle properties of a two-leg ladder model threaded by a flux with the legs coupled by a spatially varying term. Although a priori unrelated to twisted bilayer graphene (TBG), the model is found to have striking similarities: a quasi-flat low-energy band emerges with characteristics similar to that of magic angle TBG. We study the effect of interparticle interaction in our model using the density matrix renormalization group and find that when the band is quasi-flat, the ground state is a ferromagnetic Mott insulator. As the band becomes more dispersive, the system undergoes a ferromagnetic to antiferromagnetic transition. We discuss how our model is relevant not only to magic-angle physics in TBG, but also in the larger context of one-dimensional correlations and magnetism.
