论文标题
terahertz稳定拓扑材料的密度无关等离子体
Density-independent plasmons for terahertz-stable topological metamaterials
论文作者
论文摘要
为了有效地将尖端的Terahertz技术整合到紧凑的设备中，高度狭窄的Terahertz等离子体吸引了密集的关注。与金属中可见频率处的等离子体相比，通常在轻度掺杂的半导体或石墨烯中的Terahertz等离子体对载体密度（N）敏感，因此具有简单的可调性，但是，这会导致不稳定或不稳定的Terahertz光谱。通过得出简化但通用的等离子体频率形式，我们在这里揭示了在所有具有不同尺寸的拓扑状态下生成异常N独立等离子体（DIPS）的统一机制。值得注意的是，我们预测，Terahertz Dips可以在2D节点线和1D节点系统系统中激发，这是通过第一原理计算几乎所有现有的具有多种晶格对称性的拓扑半学的计算所证实的。除N独立性外，DIPS中Fermi-velocity和DeNereracy-Factor依赖性的特征可用于设计拓扑超晶格和用于宽带Terahertz Spectroscoppoy和量化Terahertz等离子体的多壁碳纳米材料的超材料。令人惊讶的是，在这些Terahertz下降中，可以同时实现高空间限制和质量因素，也对N不敏感。我们的发现铺平了为稳定的Terahertz应用开发拓扑等离子体设备的道路。
To efficiently integrate cutting-edge terahertz technology into compact devices, the highly confined terahertz plasmons are attracting intensive attentions. Compared to plasmons at visible frequencies in metals, terahertz plasmons, typically in lightly doped semiconductors or graphene, are sensitive to carrier density (n) and thus have an easy tunability, which, however, leads to unstable or imprecise terahertz spectra. By deriving a simplified but universal form of plasmon frequencies, here we reveal a unified mechanism for generating unusual n-independent plasmons (DIPs) in all topological states with different dimensions. Remarkably, we predict that terahertz DIPs can be excited in 2D nodal-line and 1D nodal-point systems, confirmed by the first-principles calculations on almost all existing topological semimetals with diverse lattice symmetries. Besides of n independence, the feature of Fermi-velocity and degeneracy-factor dependences in DIPs can be applied to design topological superlattice and multi-walled carbon nanotube metamaterials for broadband terahertz spectroscopy and quantized terahertz plasmons, respectively. Surprisingly, high spatial confinement and quality factor, also insensitive to n, can be simultaneously achieved in these terahertz DIPs. Our findings pave the way to developing topological plasmonic devices for stable terahertz applications.
