Radiative Properties and Optical Response of High-Temperature Superconducting Thin-Film Materials and Devices

建议ID：0082969标题：高温超导薄膜材料和器件的辐射特性和光学响应PI：张志军和美国佛罗里达大学的D.B.Tanner转变温度高于77K的高温超导(HTS)薄膜在量子电子学、微波和红外器件中有着广泛的应用。然而，由于其复杂的化学结构，这些材料中的电子-电子、电子-声子和电子-缺陷相互作用还没有完全被了解。了解高温超导薄膜的光学响应和输运机制对于红外辐射探测器和调制器等许多有前途的应用是至关重要的。该项目使用红外光谱来检测薄膜厚度、微结构和偏置电流对辐射性能的影响。此外，还将利用同步辐射光源测量高温超导薄膜在皮秒光激发后远红外反射率的快速变化。可调谐的法布里-珀罗谐振器将由使用压电控制器的高温超导薄膜制成。实验结果将被用来研究准粒子动力学和低频剩余损耗。薄膜-衬底界面的热阻将通过简化的动力学理论模型从时间分辨测量中确定。这个NSF项目的支持允许两名研究生接受跨学科教育，并为几名本科生提供研究经验。

AbstractProposal ID: 0082969Title: Radiative Properties and Optical Response of High-Temperature Superconducting Thin-Film Materials and DevicesPIs: Z. Zhang and D.B. Tanner, University of FloridaHigh-temperature superconducting (HTS) films with transition temperatures above 77 K have numerous applications in quantum electronics, microwave and infrared devices. However, because of their complex chemical structure, the electron-electron, electron-phonon and electron-defect interactions in these materials have not been fully understood. Understanding the optical response and transport mechanisms in HTS films is crucial for many promising applications, such as infrared radiation detectors and modulators. This project uses infrared spectroscopy to examine the effects of film thickness, microstructure, and bias currents on the radiative properties. In addition, a synchrotron radiation source will be employed to measure the rapid changes of far-infrared reflectance of HTS films after picosecond optical excitations. Tunable Fabry-Perot resonators will be built from HTS films using a piezoelectric controller. The experimental results will be analyzed to study the quasiparticle dynamics and low-frequency residual losses. The thermal boundary resistance at the film-substrate interface will be determined from time-resolved measurements using a simplified kinetic-theory model. Support from this NSF project allows cross-disciplinary education of two graduate students and provide research experience for several undergraduates.