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

Abstract

Proposal ID: 0082969

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

PIs: Z. Zhang and D.B. Tanner, University of Florida

High-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.