论文标题
双层Haldane系统：连接Chern阶段的拓扑表征和绝热段落
Bilayer Haldane system: Topological characterization and adiabatic passages connecting Chern phases
论文作者
论文摘要
我们提出了两个Chern绝缘子（特别是Haldane模型）的双层复合材料的完整拓扑表征，并明确建立了散装的对应关系。我们表明，适当定义的Chern数准确地绘制了系统的所有可能阶段，即使在被占用频段中存在归化性的情况下，也保持明确的定义。重要的是，我们的结果铺平了实现单层Chern绝缘子的绝热制备的道路。鉴于不可能单位连接不相等的拓扑阶段，这一直是迄今为止的重大挑战。我们表明，可以通过绝热地改变层间耦合来规避这种困难，从而使系统始终保持不变。特别是，对双层复合材料的相图的完整知识立即允许人们识别所有这些可能连接各个单层的Chern不相等阶段的绝热段落。
We present a complete topological characterization of a bilayer composite of two Chern insulators (specifically, Haldane models) and explicitly establish the bulk-boundary correspondences. We show that an appropriately defined Chern number accurately maps out all the possible phases of the system and remains well-defined even in the presence of degeneracies in the occupied bands. Importantly, our result paves the way for realizing adiabatic preparation of monolayer Chern insulators. This has been a major challenge till date, given the impossibility of unitarily connecting inequivalent topological phases. We show that this difficulty can be circumvented by adiabatically varying the interlayer coupling in such a way that the system remains gapped at all times. In particular, a complete knowledge of the phase diagram of the bilayer composite immediately allows one to identify all such adiabatic passages which may connect the different Chern inequivalent phases of the individual monolayers.
