论文标题
在扩展的Haldane-Hubbard模型中，本地秩序和拓扑的相互作用
Interplay of local order and topology in the extended Haldane-Hubbard model
论文作者
论文摘要
我们使用精确的二进制化，平均场变异方法研究了蜂窝状晶格上综合的扩展Haldane-Hubbard模型的地面相图，并将其进一步与无限密度基质重质化基团相互补充，该基质施加在无限的蜂窝缸上。该模型受现场和最近的邻居相互作用的控制，可以导致两种具有有限局部顺序参数的绝缘体，无论是旋转还是充电顺序。此外，第三个是具有非本地秩序的拓扑非平凡的绝缘子，也很明显。我们测试了先前分析的期望，在无旋转版本中断言，一旦形成了局部顺序参数，就不再存在与有限的Chern数量相关的基态特征，即导致拓扑琐事波函数。我们的研究证实了这一整体情况，并强调了有限尺寸的影响如何导致对有限的局部顺序参数共存和该模型中非平凡拓扑的共存的误导性结论。
We investigate the ground-state phase diagram of the spinful extended Haldane-Hubbard model on the honeycomb lattice using an exact-diagonalization, mean-field variational approach, and further complement it with the infinite density matrix renormalization group, applied to an infinite honeycomb cylinder. This model, governed by both on-site and nearest-neighbor interactions, can result in two types of insulators with finite local order parameters, either with spin or charge ordering. Moreover, a third one, a topologically nontrivial insulator with nonlocal order, is also manifest. We test expectations of previous analyses in spinless versions asserting that once a local order parameter is formed, the topological characteristics of the ground state, associated with a finite Chern number, are no longer present, resulting in a topologically trivial wave function. Our study confirms this overall picture, and highlights how finite-size effects may result in misleading conclusions on the coexistence of finite local order parameters and nontrivial topology in this model.
