Exceptional surfaces in PT-symmetric non-Hermitian photonic systems
Exceptional surfaces in PT-symmetric non-Hermitian photonic systems
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DOI：
10.1364/optica.6.000190
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发表时间：
2018-10
期刊：
影响因子：
10.4
通讯作者：
Hengyun Zhou;Jong Yeon Lee;Shang Liu;B. Zhen
中科院分区：
文献类型：
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作者：
Hengyun Zhou;Jong Yeon Lee;Shang Liu;B. Zhen
非厄米特系统中的例外点最近被证明具有非平凡的拓扑性质，并产生许多奇异的物理现象。然而，到目前为止，大多数研究都集中在孤立的例外点或例外点的一维直线上。在这里，我们通过设计例外点的二维曲面来大大扩展例外系统的空间，并发现对称性是保护这种例外曲面的关键因素。我们利用拓扑节线的对称保持非厄米变形来构造它们，并分析了与之相关的对称性、拓扑学和物理后果。作为一个潜在的实现，我们模拟了一个宇称时间对称的三维光子晶体，确实发现了异常表面的出现。我们的工作为未来探索高维的例外点系统，以及在排放控制和传感方面的应用铺平了道路。
Exceptional points in non-Hermitian systems have recently been shown to possess nontrivial topological properties and to give rise to many exotic physical phenomena. However, most studies thus far have focused on isolated exceptional points or one-dimensional lines of exceptional points. Here, we substantially expand the space of exceptional systems by designing two-dimensional surfaces of exceptional points, and find that symmetries are a key element to protect such exceptional surfaces. We construct them using symmetry-preserving non-Hermitian deformations of topological nodal lines, and analyze the associated symmetry, topology, and physical consequences. As a potential realization, we simulate a parity-time-symmetric 3D photonic crystal and indeed find the emergence of exceptional surfaces. Our work paves the way for future explorations of systems of exceptional points in higher dimensions, and applications in emission control and sensing.