论文标题
四分之一填充的拓扑莫特绝缘子
Topological Mott Insulator at Quarter Filling in the Interacting Haldane Model
论文作者
论文摘要
虽然拓扑的最新进展导致了标准金属理论描述的电子频段的分类方案，但对于诸如Mott绝缘体等密切相关的系统，尚未出现类似的方案，其中部分填充的频带没有电流。通过在拓扑非平凡的霍尔丹模型中加入相互作用，我们表明，如果相互作用足够大，则以非零的Chern数出现了四分之一的状态。我们首先是基于物理基础，然后通过两种方法来激励这种结果：通过求解一个模型，其中相互作用在动量空间中是局部的，然后通过相应的Hubbard模型在数值上是局部的。所有方法都产生相同的结果：对于足够大的相互作用强度，四分之一填充的Haldane模型是具有Chern数量统一数的铁磁拓扑莫特绝缘子。讨论了冷原子和固态系统中可能的实验实现。
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.
