Topological Mott insulator at quarter filling in the interacting Haldane model
Topological Mott insulator at quarter filling in the interacting Haldane model
复制标题
DOI：
10.1103/physrevresearch.5.013162
复制
发表时间：
2022-07
影响因子：
4.2
通讯作者：
P. Mai;B. Feldman;P. Phillips
中科院分区：
文献类型：
--
作者：
P. Mai;B. Feldman;P. Phillips
尽管拓扑学的最新进展已催生出一套用于描述金属标准理论所涉及电子能带的分类方案，但对于强关联体系，如部分填充能带不导电的莫特绝缘体，类似方案却尚未出现。通过在拓扑非平凡的霍尔丹模型中纳入相互作用，我们发现，只要相互作用足够强，就会出现具有非零陈数的四分之一填充态。我们首先从物理层面阐述这一结果的合理性，然后通过两种方法加以论证：一是通过精确求解相互作用在动量空间局域的模型进行解析论证，二是通过相应的哈伯德模型进行数值论证。所有方法都得出相同结果：当相互作用强度足够大时，四分之一填充的霍尔丹模型是一种陈数为1的铁磁拓扑莫特绝缘体。文中还讨论了在冷原子和固态系统中可能的实验实现方式。
While the recent advances in topology have led to a classification scheme for electronic bands described by the standard theory of metals, a similar scheme has not emerged for strongly correlated systems such as Mott insulators in which a partially filled band carries no current. By including interactions in the topologically non-trivial Haldane model, we show that a quarter-filled state emerges with a non-zero Chern number provided the interactions are sufficiently large. We first motivate this result on physical grounds and then by two methods: analytically by solving exactly a model in which interactions are local in momentum space and then numerically through the corresponding Hubbard model. All methods yield the same result: For sufficiently large interaction strengths, the quarter-filled Haldane model is a ferromagnetic topological Mott insulator with a Chern number of unity. Possible experimental realizations in cold-atom and solid state systems are discussed.