论文标题
由定期调制的声子孔形成的横向超晶
Transverse hypercrystals formed by periodically modulated phonon-polaritons
论文作者
论文摘要
光子晶体和超材料是操纵光的两个总体范式。结合两种方法会导致过度晶体：双曲线分散剂的超材料经过周期性调节并将光子晶体样方面与双曲线分散体物理学混合在一起。到目前为止，由于各种技术和设计限制，超晶体的实验实现有限。在这里，我们创建了纳米级超晶体，其晶格常数范围为25 nm至160 nm，并通过散射近场显微镜测量其集体Bloch模式和分散。我们首次证明了分散特征，例如负速度，表明带折叠的状态和尖峰密度的特征，预期的是超晶体（而不是普通的极化晶体）。这些密度峰将我们的发现与即使在几何简单的晶格中出现的极富丰富的超晶体结构的理论预测联系在一起。这些功能使超晶体从根本上有趣，也使工程纳米级轻相互作用的潜在用途。
Photonic crystals and metamaterials are two overarching paradigms for manipulating light. Combining the two approaches leads to hypercrystals: hyperbolic dispersion metamaterials that undergo periodic modulation and mix photonic-crystal-like aspects with hyperbolic dispersion physics. So far, there has been limited experimental realization of hypercrystals due to various technical and design constraints. Here, we create nanoscale hypercrystals with lattice constants ranging from 25 nm to 160 nm and measure their collective Bloch modes and dispersion with scattering nearfield microscopy. We demonstrate for the first time dispersion features such as negative group velocity, indicative of bandfolding, and signatures of sharp density of states peaks, expected for hypercrystals (and not for ordinary polaritonic crystals). These density peaks connect our findings to the theoretical prediction of an extremely rich hypercrystal bandstructure emerging even in geometrically simple lattices. These features make hypercrystals both fundamentally interesting, as well as of potential use to engineering nanoscale light-matter interactions.
