It was recently proposed (P A Brandão and S B Cavalcanti 2019 Phys. Rev. A 100 043822) that two small (Dirac) scatterers, one having gain and the other having loss, drastically modifies the spectral density of the scattered radiation field. Here, we extend this previous work by studying the scattering of stochastic radiation by two finite spheres having gain and loss, satisfying the parity-time symmetry condition, and verifying the spectral changes in frequency domain, i.e. the non-Hermitian Wolf effect. Under the Born approximation, we analytically found the specific frequencies where the spectral density of the scattered field vanishes and show that they depend on the gain and loss parameter γ of each material. This is evidence of a non-Hermitian Wolf effect, meaning that the spectrum can be tuned by the gain/loss properties of the system. We have also shown that there is a π /2 phase shift when ##IMG## [http://ej...] {$\gamma \gg 1$}

中文翻译：

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具有奇偶时间对称性的两个球散射多色辐射的沃尔夫效应

最近提出（PABrandão和SB Cavalcanti 2019 Phys.Rev.A 100 043822），两个小（狄拉克）散射体，其中一个具有增益而另一个具有损耗，极大地改变了散射辐射场的光谱密度。在这里，我们通过研究具有增益和损耗的两个有限球体对随机辐射的散射，满足奇偶时间对称性条件，并验证频域中的频谱变化（即非Hermitian Wolf效应）来扩展先前的工作。在Born近似下，我们分析地发现了散射场的频谱密度消失的特定频率，并表明它们取决于每种材料的增益和损耗参数γ。这是非埃尔米特沃尔夫效应的证据，这意味着可以通过系统的增益/损耗特性来调整频谱。