近日，南开大学的金亮教授及其研究小组取得一项新进展。经过不懈努力，他们发现了高阶谱奇点。相关研究成果已于2023年6月9日在国际知名学术期刊《物理评论A》上发表。
这项研究报道了非厄米散射系统中的高阶谱奇点现象，即散射矩阵的高阶极点。这些高阶谱奇点是异常点和光谱奇点的统一体现。在高阶谱奇点处，散射系数呈现高阶发散，从而激发出高阶激光效应。波的辐射强度通过多项式增强，其增长阶数与光谱奇点的阶数线性相关。此外，相干输入能够控制和改变光谱奇点的阶数。这些发现深入揭示了高阶谱奇点的基础原理和潜在应用价值。
据介绍，异常点和光谱奇点是非厄米系统中独特的两种奇点。
附：英文原文
Title: High-order spectral singularity
Author: H. S. Xu, L. C. Xie, L. Jin
Issue&Volume: 2023/06/09
Abstract: Exceptional point and spectral singularity are two types of singularity that are unique to non-Hermitian systems. Here, we report the high-order spectral singularity as a high-order pole of the scattering matrix for a non-Hermitian scattering system, and the high-order spectral singularity is a unification of the exceptional point and spectral singularity. At the high-order spectral singularity, the scattering coefficients have high-order divergence and the scattering system stimulates high-order lasing. The wave emission intensity is polynomially enhanced, and the order of the growth in the polynomial intensity linearly scales with the order of the spectral singularity. Furthermore, the coherent input controls and alters the order of the spectral singularity. Our findings provide profound insights into the fundamentals and applications of high-order spectral singularities.
DOI: 10.1103/PhysRevA.107.062209
Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.107.062209
来源：科学网 小柯机器人