Corner states of light in photonic waveguides
Corner states of light in photonic waveguides
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DOI：
10.1038/s41566-019-0519-y
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发表时间：
2019-10-01
期刊：
影响因子：
35
通讯作者：
Bourennane, Mohamed
中科院分区：
文献类型：
--
作者：
El Hassan, Ashraf;Kunst, Flore K.;Bourennane, Mohamed
最近建立的高阶拓扑物质态的范例表明，不仅边缘和表面态（1，2），而且局限于角落的状态，可以具有强大的和奇异的属性（3-9）。在这里，我们报告的实验实现的新的角状态的可见光在三维光子结构刻在玻璃样品中使用飞秒激光技术（10，11）。通过创建和分析波导阵列，形成二维呼吸kagome晶格在各种样品的几何形状，我们建立了这个作为一个平台的角状态表现出显着程度的灵活性和控制。在每个样品的几何形状中，我们测量了在有限频率范围内位于拐角处的本征模，这与呼吸kagome的理论模型完全相似（7- 9，12 -14）。在这里，测量表明，光可以被“细分”，对应于同时定位到三角形样品的每个角落，即使在存在缺陷的情况下。
The recently established paradigm of higher-order topological states of matter has shown that not only edge and surface states(1,2) but also states localized to corners, can have robust and exotic properties(3-9). Here we report on the experimental realization of novel corner states made out of visible light in three-dimensional photonic structures inscribed in glass samples using femtosecond laser technology(10,11). By creating and analysing waveguide arrays, which form two-dimensional breathing kagome lattices in various sample geometries, we establish this as a platform for corner states exhibiting a remarkable degree of flexibility and control. In each sample geometry we measure eigenmodes that are localized at the corners in a finite frequency range, in complete analogy with a theoretical model of the breathing kagome(7-9,12-14). Here, measurements reveal that light can be 'fractionalized,' corresponding to simultaneous localization to each corner of a triangular sample, even in the presence of defects.