Probing the Band Structure of Topological Silicon Photonic Lattices in the Visible Spectrum
Probing the Band Structure of Topological Silicon Photonic Lattices in the Visible Spectrum
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DOI：
10.1103/physrevlett.122.117401
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发表时间：
2019-03-21
影响因子：
8.6
通讯作者：
Polman, Albert
中科院分区：
文献类型：
--
作者：
Peng, Siying;Schilder, Nick J.;Polman, Albert
研究了可见光谱范围内具有拓扑光学能带结构的硅Mie谐振器的二维六方光子晶格。我们使用30keV的电子聚焦到纳米尺度的光斑，以深亚波长分辨率映射了拓扑光子晶格中的局域态密度。通过微缩或膨胀晶胞，我们形成了六方超结构，并观察到与拓扑平凡和非平凡相对应的双简并狄拉克锥体的带隙打开和分裂。光学透射谱表明，在拓扑晶格和平凡晶格之间的域壁上存在拓扑边缘状态的证据。
We study two-dimensional hexagonal photonic lattices of silicon Mie resonators with a topological optical band structure in the visible spectral range. We use 30 keV electrons focused to nanoscale spots to map the local optical density of states in topological photonic lattices with deeply subwavelength resolution. By slightly shrinking or expanding the unit cell, we form hexagonal superstructures and observe the opening of a band gap and a splitting of the double-degenerate Dirac cones, which correspond to topologically trivial and nontrivial phases. Optical transmission spectroscopy shows evidence of topological edge states at the domain walls between topological and trivial lattices.