论文标题
二维拓扑绝缘子中的等离子体
Plasmons in Two-Dimensional Topological Insulators
论文作者
论文摘要
我们使用随机相近似分析了二维拓扑绝缘子模型中的集体激发。在Su-Schrieffer-Heeger模型的二维扩展中，在系统边界的诱导电荷密度分布的边缘等离子体激发在拓扑上是非平整的相位，在常规的Su-Schrieffer-Hee-Heger链中的一维散装等离子相似。对于二维批量集体模式，我们揭示了增强的带间波函数相关性的机制，从而分别导致型和内部和内部内部和内部散装等离激元分支的特征性硬化和软化。在二维Haldane Chern绝缘子模型中，观察到纳米 - 丝本架构中的手性，单向边缘等离子体，可以通过有效的库仑相互作用横截面来表征。二维HALDANE模型中的散装集体激发显示出由不同拓扑阶段的单粒子带结构细节起源。
We analyze collective excitations in models of two-dimensional topological insulators using the random phase approximation. In a two-dimensional extension of the Su-Schrieffer-Heeger model, edge plasmonic excitations with induced charge-density distributions localized at the boundaries of the system are found in the topologically non-trivial phase, dispersing similarly as one-dimensional bulk plasmons in the conventional Su-Schrieffer-Heeger chain. For two-dimensional bulk collective modes, we reveal regimes of enhanced inter-band wave function correlations, leading to characteristic hardening and softening of inter- and intra-band bulk plasmonic branches, respectively. In the two-dimensional Haldane Chern insulator model, chiral, uni-directional edge plasmons in nano-ribbon architectures are observed, which can be characterized by an effective Coulomb interaction cross section. Bulk collective excitations in the two-dimensional Haldane model are shown to be originated by single-particle band structure details in different topological phases.
