Wang Xilan, Hao Ran, Fan Pengtao, Hu Luoshu, Ye Bilin, Zou Yonggang, Jin Shangzhong
Opt Lett. 2024 Feb 1;49(3):554-557. doi: 10.1364/OL.513800.
With the rich physical phenomena arising from non-Hermitian systems, the non-Hermitian skin effect (NHSE) has become a current research hotspot. Nowadays, the corner skin effect based on non-reciprocal photonic crystals has been proposed. Considering the complexity of realizing non-reciprocity, the corner skin effect based on reciprocal photonic crystals is well worth investigating. In this Letter, a non-Hermitian reciprocal geometry-dependent corner skin effect based on two-dimensional photonic crystals is presented, which is manifested as the distribution of eigenstates on the corners of a particular geometry by applying open boundary conditions in both directions of photonic crystals. For the better application of the NHSE in the future, such as highly sensitive sensors and lasers, a new, to the best of our knowledge, method that can effectively enhance the performance of the NHSE in photonic crystals is proposed. The method introduces both gain and loss in an ideal photonic crystal to enhance the non-Hermitian specificity of the system, which improves the performance of the non-Hermitian corner skin effect of photonic crystals by 64.5%. Furthermore, this geometry-dependent corner skin effect is corroborated with the spectral topology.
随着非厄米系统中出现丰富的物理现象，非厄米趋肤效应（NHSE）已成为当前的研究热点。如今，基于非互易光子晶体的角趋肤效应已被提出。考虑到实现非互易性的复杂性，基于互易光子晶体的角趋肤效应很值得研究。在本信函中，提出了一种基于二维光子晶体的非厄米互易几何依赖角趋肤效应，通过在光子晶体的两个方向上应用开放边界条件，其表现为特定几何形状角上的本征态分布。为了未来更好地应用NHSE，例如用于高灵敏度传感器和激光器，我们提出了一种据我们所知能有效提高光子晶体中NHSE性能的新方法。该方法在理想光子晶体中同时引入增益和损耗以增强系统的非厄米特异性，这使得光子晶体的非厄米角趋肤效应性能提高了64.5%。此外，这种几何依赖角趋肤效应通过光谱拓扑得到了证实。
