发表机构
Peking University; Shanxi University; Hefei National Laboratory（北京大学; 山西大学; 合肥国家实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出广义平方根方法，从n阶EP母哈密顿量构造手性对称EP_{2n+1}系统，实现多重光谱响应，为信号放大与检测提供普适平台。
AI 中文摘要
我们将平方根过程推广到具有有限格点的非厄米系统中，提供了一种适用于任意紧束缚模型的光谱操作方案。通过这种广义平方根方法，我们构建了具有多重光谱响应的新型手性对称高阶例外点（EPs）。通过对一个拥有n阶例外点（EP_n）的母哈密顿量取平方根，我们得到一个EP_{2n+1}手性对称平方根系统，其格点继承自母系统和辅助残余系统。手性对称性诱导的广义特征空间结构使得在位和耦合扰动能够选择性地产生不同阶数的光谱响应。所提出的方案具有普适性，适用于任何现有的紧束缚EP系统，并且可以迭代生成任意高阶的EP。凭借丰富化的超灵敏光谱响应，手性对称高阶EP系统为信号放大、检测和非厄米控制提供了一个有前景的平台。
英文摘要
We generalize square-root procedure to non-Hermitian systems with finite lattices, providing a spectral operation scheme applicable to arbitrary tight-binding models. Via this generalized square-root approach, we construct novel chiral-symmetric higher-order exceptional points (EPs) with multiple spectral responses. By taking square-root of a parent Hamiltonian hosting an $n$th-order EP (EP$_n$), an EP$_{2n+1}$ chiral-symmetric square-root system is obtained, whose lattice sites are inherited from both the parent system and an auxiliary residual system. The chiral-symmetry-induced structure of the generalized eigenspace enables onsite and coupling perturbations to selectively generate spectral responses of different orders. The proposed scheme is universal, applicable to any existing tight-binding EP system and iterable to generate EPs of arbitrarily high order. With enriched ultrasensitive spectral responses, the chiral-symmetric higher-order EP system provides a promising platform for signal amplification, detection and non-Hermitian control.
Comments6 pages, 3 figures
