论文标题
探索扩展Su-Schrieffer-Heeger模型的交互性拓扑绝缘子
Exploring interacting topological insulator of extended Su-Schrieffer-Heeger model
论文作者
论文摘要
在交互系统中探索拓扑阶段是一项艰巨的任务。我们研究了扩展的su-schrieffer-heeger（SSH）模型中相互作用费物的多体拓扑物理学，该模型将SSH模型的两个sSH模型的两个sblattices扩展到了四个sublattices中，因此根据密度 - 恢复性renalization-Renoralization-ralitalization-namerical Numerical numerical方法将SSH4模型称为SSH4模型。可以通过分析纠缠频谱，纠缠熵，能量差距，CDW顺序参数和保真度的变化来识别从拓扑绝缘体到电荷密度波（CDW）相的相互作用驱动的相变。我们绘制了多体基态的全局相图，该状态分别包含非平凡的拓扑绝缘子，微不足道的绝缘子和CDW相。与相互作用的SSH模型相反，在该模型中，向CDW相的相变为一阶相变，CDW相位与拓扑上的琐碎/非平凡阶段之间的相变是连续的相变。最后，我们{也}显示了相互作用的跨度SSH4模型的相图，其中有吸引力的（排斥）现场自旋相互作用放大（抑制）CDW相。这里分析的模型可以使用光学超晶格上的超电原子实现。
Exploring topological phases in interacting systems is a challenging task. We investigate many-body topological physics of interacting fermions in an extended Su-Schrieffer-Heeger (SSH) model, which extends the two sublattices of SSH model into four sublattices and thus is dubbed SSH4 model, based on the density-matrix renormalization-group numerical method. The interaction-driven phase transition from topological insulator to charge density wave (CDW) phase can be identified by analyzing the variations of entanglement spectrum, entanglement entropies, energy gaps, CDW order parameter, and fidelity. We map the global phase diagram of the many-body ground state, which contains nontrivial topological insulator, trivial insulator and CDW phases, respectively. In contrast to interacting SSH model, in which the phase transitions to the CDW phase are argued to be first-order phase transitions, the phase transitions between the CDW phase and topologically trivial/nontrivial phases are shown to be continuous phase transitions. Finally, we {also} show the phase diagram of interacting spinful SSH4 model, where the attractive (repulsive) on-site spin interaction amplifies (suppresses) the CDW phase. The models analyzed here can be implemented with ultracold atoms on optical superlattices.
