Chen Lei, Anlage Steven M
Maryland Quantum Materials Center, Department of Physics, University of Maryland, College Park, Maryland 20742, USA and Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742, USA.
Phys Rev E. 2022 May;105(5-1):054210. doi: 10.1103/PhysRevE.105.054210.
We identify the poles and zeros of the scattering matrix of a simple quantum graph by means of systematic measurement and analysis of Wigner, transmission, and reflection complex time delays. We examine the ring graph because it displays both shape and Feshbach resonances, the latter of which arises from an embedded eigenstate on the real frequency axis. Our analysis provides a unified understanding of the so-called shape, Feshbach, electromagnetically induced transparency, and Fano resonances on the basis of the distribution of poles and zeros of the scattering matrix in the complex frequency plane. It also provides a first-principles understanding of sharp resonant scattering features and associated large time delay in a variety of practical devices, including photonic microring resonators, microwave ring resonators, and mesoscopic ring-shaped conductor devices. Our analysis involves use of the reflection time difference, as well as a comprehensive use of complex time delay, to analyze experimental scattering data.
我们通过对维格纳、透射和反射复时间延迟进行系统测量与分析，来确定一个简单量子图散射矩阵的极点和零点。我们研究环形图，因为它既展示了形状共振又展示了费什巴赫共振，后者源于实频率轴上的一个嵌入本征态。我们的分析基于散射矩阵在复频率平面上的极点和零点分布，对所谓的形状共振、费什巴赫共振、电磁诱导透明和法诺共振提供了统一的理解。它还对包括光子微环谐振器、微波环形谐振器和介观环形导体器件在内的各种实际器件中的尖锐共振散射特征及相关的大时间延迟提供了第一性原理的理解。我们的分析涉及使用反射时间差以及综合运用复时间延迟来分析实验散射数据。
