Experimental observation of the topological structure of exceptional points
Experimental observation of the topological structure of exceptional points
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DOI：
10.1103/physrevlett.86.787
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发表时间：
2001-01-29
影响因子：
8.6
通讯作者：
Richter, A
中科院分区：
文献类型：
--
作者：
Dembowski, C;Gräf, HD;Richter, A
我们报告的微波腔实验例外点（EP），这是平方根奇异的本征值作为一个复杂的相互作用参数的函数，在实验室中被包围。本征值的真实的实部和虚部由谐振的频率和宽度给出，本征向量由场分布给出。排斥的特征值总是与EP-意味着频率anticrossing（交叉）时，宽度交叉（anticrossing）。本征值和本征向量在环绕EP时互换，但其中一个本征向量经历了可以在场模式中辨别的符号变化。
We report on a microwave cavity experiment where exceptional points (EPs), which are square root singularities of the eigenvalues as function of a complex interaction parameter, are encircled in the laboratory. The real and imaginary parts of an eigenvalue are given by the frequency and width of a resonance and the eigenvectors by the field distributions. Repulsion of eigenvalues-always associated with EPs-implies frequency anticrossing (crossing) whenever width crossing (anticrossing) is present. The eigenvalues and eigenvectors are interchanged while encircling an EP, but one of the eigenvectors undergoes a sign change which can be discerned in the field patterns.