Observation of a nonradiative flat band for spoof surface plasmons in a metallic Lieb lattice
Observation of a nonradiative flat band for spoof surface plasmons in a metallic Lieb lattice
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DOI：
10.1103/physrevb.93.075126
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发表时间：
2016-02-12
影响因子：
3.7
通讯作者：
Kitano, Masao
中科院分区：
文献类型：
--
作者：
Kajiwara, Sho;Urade, Yoshiro;Kitano, Masao
在太赫兹区，我们证明了在具有Lieb晶格对称性的结构表面上束缚的欺骗表面等离子体激元的无辐射平坦带。首先，在电路模型的基础上，从理论上推导了金属Lieb晶格中欺骗等离子体的色散关系。我们得到了三个频带，其中一个与波矢无关。为了验证理论结果，我们对透射型和衰减型全反射结构中的平带进行了数值和实验观察。我们发现非辐射平带模与传播波去耦合后的品质因数比辐射平带模的品质因数高。这表明无辐射的平带模在晶格中是三维受限的。
We demonstrate a nonradiative flat band for spoof surface plasmon polaritons bounded on a structured surface with Lieb lattice symmetry in the terahertz regime. First, we theoretically derive the dispersion relation of spoof plasmons in a metallic Lieb lattice based on the electrical circuit model. We obtain three bands, one of which is independent of wave vector. To confirm the theoretical result, we numerically and experimentally observe the flat band in transmission and attenuated total reflection configurations. We reveal that the quality factor of the nonradiative flat-band mode decoupled from the propagating wave is higher than that of the radiative flat-band mode. This indicates that the nonradiative flat-band mode is three-dimensionally confined in the lattice.