Pair of Exceptional Points in a Microdisk Cavity under an Extremely Weak Deformation.
Pair of Exceptional Points in a Microdisk Cavity under an Extremely Weak Deformation.
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DOI：
10.1103/physrevlett.120.093902
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发表时间：
2018-02
影响因子：
8.6
通讯作者：
Changhwan Yi;Julius Kullig;J. Wiersig
中科院分区：
文献类型：
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作者：
Changhwan Yi;Julius Kullig;J. Wiersig
开放量子和波动系统的一个有趣的特征是非厄米简并性，称为例外点，在那里不仅能级而且相应的本征态合并。我们证明，这种简并可以出现在光盘腔的边界变形非常微弱。这个令人惊讶的发现可以用半经典动力学隧穿理论来解释。它示出的例外点来在几乎退化的对，源自不同的对称类的模式。异常点处的模式的空间局部手征性与坡印亭矢量的涡旋结构有关。
One of the interesting features of open quantum and wave systems is the non-Hermitian degeneracy called an exceptional point, where not only energy levels but also the corresponding eigenstates coalesce. We demonstrate that such a degeneracy can appear in optical microdisk cavities by deforming the boundary extremely weakly. This surprising finding is explained by a semiclassical theory of dynamical tunneling. It is shown that the exceptional points come in nearly degenerated pairs, originating from the different symmetry classes of modes. A spatially local chirality of modes at the exceptional point is related to vortex structures of the Poynting vector.