Nonlinearity-enabled higher-order exceptional singularities with ultra-enhanced signal-to-noise ratio.
Nonlinearity-enabled higher-order exceptional singularities with ultra-enhanced signal-to-noise ratio.
复制标题
非线性使高阶异常奇点具有超增强的信噪比
DOI：
10.1093/nsr/nwac259
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发表时间：
2023-07
影响因子：
20.6
通讯作者：
中科院分区：
文献类型：
--
作者：
具有非凡响应性的高阶异常点(HOEP)有望在与检测相关的应用中表现出极大的改进性能。然而，在过去的几年里，这种方法由于几个潜在的缺点而受到质疑，包括严格的参数要求、基本分辨率限制和噪声。在这里，我们探讨了非线性增益饱和在非厄米特系统的例外奇点中的后果，为克服上述困难提供了一个可行的方案。我们提供了一个简单直观的例子，通过理论和电路实验演示了一种仅在两个耦合谐振器中借助于非线性增益而具有超强信噪比(SNR)的HOEP。将六维超维空间中繁琐的参数调整简化为两维空间。非线性饱和增益的反馈机制可以解决其他线性系统中关于EPs信噪比的争论。我们的发现促进了对非线性非厄米系统特殊拓扑结构的基本理解，显著降低了EP传感的实际难度，并可能为其应用开辟新的途径。对非线性增益饱和的探索结束了关于特殊奇点附近非增强型信噪比的长期争论，从而为有前途的超灵敏传感器件铺平了道路。
Higher-order exceptional points (HOEPs) with extraordinary responsivity are expected to exhibit a vastly improved performance in detection-related applications. However, over the past few years, such an approach has been questioned due to several potential drawbacks, including the stringent parameter requirements, fundamental resolution limits and noise. Here, exploring the consequence of nonlinear gain saturation in exceptional singularities of non-Hermitian systems, we offer a feasible scheme to overcome all the above difficulties. We provide a simple and intuitive example by demonstrating with both theory and circuit experiments an ‘exceptional nexus’ (‘EX’), a HOEP with an ultra-enhanced signal-to-noise ratio (SNR), in only two coupled resonators with the aid of nonlinear gain. The tedious parameter tuning in a six-dimensional hyper-dimensional space is reduced to two dimensions. The feedback mechanism of nonlinear saturable gain can give a solution to the ongoing debate on the SNR of EPs in other linear systems. Our findings advance the fundamental understanding of the peculiar topology of nonlinear non-Hermitian systems, significantly reduce the practical difficulty in EP sensing and possibly open new avenues for applications. Exploring the nonlinear gain saturation ends a long-lasting debate about non-enhanced signal-to-noise ratio in the proximity of exceptional singularities, and thus paves the way for promising ultrasensitive sensing devices.
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影响因子：
8.6
作者：
Bender, CM;Boettcher, S
通讯作者：
Boettcher, S
影响因子：
8.6
作者：
Leykam, Daniel;Chong, Y. D.
通讯作者：
Chong, Y. D.
影响因子：
8.6
作者：
Ding, Kun;Ma, Guancong;Chan, C. T.
通讯作者：
Chan, C. T.
影响因子：
1.4
作者：
HEISS, WD
通讯作者：
HEISS, WD
影响因子：
2.9
作者：
Langbein, W.
通讯作者：
Langbein, W.