Yin Shixiong, Alù Andrea
Department of Electrical Engineering, City College of The City University of New York, New York 10031, USA.
Photonics Initiative, Advanced Science Research Center, The City University of New York, New York 10031, USA.
Nanophotonics. 2023 Mar 30;12(14):2963-2971. doi: 10.1515/nanoph-2023-0062. eCollection 2023 Jul.
Periodic arrays can support highly nontrivial modal dispersion, stemming from the interplay between localized resonances of the array elements and distributed resonances supported by the lattice. Recently, intentional defects in the periodicity, i.e., broken symmetries, have been attracting significant attention as a powerful degree of freedom for dispersion control. Here we explore highly nontrivial dispersion features in the resonant response of linear arrays of plasmonic particles, including the emergence of braiding and band knots caused by band folding. We show that these phenomena can be achieved within simple dipolar arrays for which we can derive closed-form expressions for the dispersion relation. These phenomena showcase powerful opportunities stemming from broken symmetries for extreme dispersion engineering, with a wide range of applications, from plasma physics to topological wave phenomena. Our theoretical model can also be generalized to higher dimensions to explore higher-order symmetries, e.g., glide symmetry and quasi-periodicity.
周期性阵列能够支持高度非平凡的模式色散，这源于阵列元件的局域共振与晶格所支持的分布式共振之间的相互作用。近来，周期性中的有意缺陷，即对称性破缺，作为色散控制的一个强大自由度，已引起了广泛关注。在此，我们探究了等离子体粒子线性阵列共振响应中的高度非平凡色散特性，包括由能带折叠导致的编织和能带结的出现。我们表明，这些现象可以在简单的偶极子阵列中实现，对于此类阵列，我们可以推导出色散关系的封闭形式表达式。这些现象展示了对称性破缺为极端色散工程带来的强大机遇，具有广泛的应用，从等离子体物理到拓扑波现象。我们的理论模型还可以推广到更高维度，以探索更高阶的对称性，例如滑移对称性和准周期性。
