Experimental Demonstration of an Anisotropic Exceptional Point
Experimental Demonstration of an Anisotropic Exceptional Point
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DOI：
10.1103/physrevlett.121.085702
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发表时间：
2018-08-21
影响因子：
8.6
通讯作者：
Chan, C. T.
中科院分区：
文献类型：
--
作者：
Ding, Kun;Ma, Guancong;Chan, C. T.
在许多非厄米特系统中发现了与平方根奇点相关的例外点。在大多数研究中，发现的EP是各向同性的，这意味着相同的奇异行为是独立的方向，他们在参数空间中接近。在这封信中，我们从理论上和实验上证明了各向异性EP在声学系统中的存在，当各向异性EP从参数空间中的不同方向接近时，该声学系统表现出不同的奇异行为。这种各向异性EP产生于具有相同手性的两个平方根EP的合并。
Exceptional points (EPs) associated with a square-root singularity have been found in many non-Hermitian systems. In most of the studies, the EPs found are isotropic, meaning that the same singular behavior is obtained independent of the direction from which they are approached in the parameter space. In this Letter, we demonstrate both theoretically and experimentally the existence of an anisotropic EP in an acoustic system that shows different singular behaviors when the anisotropic EP is approached from different directions in the parameter space. Such an anisotropic EP arises from the coalescence of two square-root EPs having the same chirality.