Generalization of Wigner time delay to subunitary scattering systems
Generalization of Wigner time delay to subunitary scattering systems
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DOI：
10.1103/physreve.103.l050203
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发表时间：
2021-05-18
影响因子：
2.4
通讯作者：
Fyodorov, Yan, V
中科院分区：
文献类型：
--
作者：
Chen, Lei;Anlage, Steven M.;Fyodorov, Yan, V
我们介绍了一个复杂的推广的维格纳时间延迟τ次酉散射系统。给出了作为激励能量、均匀和非均匀损耗以及耦合函数的复时滞的理论表达式。我们发现非常好的理论和实验数据之间的协议微波图形包含一个电子可变的集中损耗元件。我们发现，时间延迟和散射矩阵的行列式有一个共同的特点，即Re[tau]和Im[tau]中的共振行为是相干完全吸收（CPA）条件的可靠指标。通过加强有耗系统中的时间延迟的概念，这项工作提供了一种手段，以确定从实验数据的散射矩阵的极点和零点。研究结果还为在复杂散射系统中实现任意频率的CPA提供了一种方法。
We introduce a complex generalization of the Wigner time delay tau for subunitary scattering systems. Theoretical expressions for complex time delays as a function of excitation energy, uniform and nonuniform loss, and coupling are given. We find very good agreement between theory and experimental data taken on microwave graphs containing an electronically variable lumped-loss element. We find that the time delay and the determinant of the scattering matrix share a common feature in that the resonant behavior in Re[tau] and Im[tau] serves as a reliable indicator of the condition for coherent perfect absorption (CPA). By reinforcing the concept of time delays in lossy systems this work provides a means to identify the poles and zeros of the scattering matrix from experimental data. The results also enable an approach to achieving CPA at an arbitrary frequency in complex scattering systems.