Measurement of Local Reactive and Resistive Photoresponse of a Superconducting Microwave Device

TL;DR

This paper introduces a spatial partition method to analyze the local reactive and resistive photoresponse of superconducting microwave devices, revealing defect-related sources of nonlinear high-frequency behavior.

Contribution

The study presents a novel spatial partition technique combined with laser scanning microscopy to identify defect-induced nonlinear responses in superconducting microwave devices.

Findings

Resistive losses mainly originate from local defects and weak links.

Defects cause nonlinear high-frequency responses through vortex entry.

The method correlates spatial defect locations with photoresponse characteristics.

Abstract

We propose and demonstrate a spatial partition method for the high-frequency photo-response of superconducting devices correlated with inductive and resistive changes in microwave impedance. Using a laser scanning microscope, we show that resistive losses are mainly produced by local defects at microstrip edges and by intergrain weak links in the high-temperature superconducting material. These defects initiate nonlinear high-frequency response due to overcritical current densities and entry of vortices.