Local Whole-Device Scanning of Distortion in Superconducting Microwave Resonators

TL;DR

This paper introduces a near-field microwave imaging technique to map and analyze the spatial distribution of intermodulation distortion in superconducting microwave resonators, revealing different physical mechanisms for second and third order IMD.

Contribution

It presents a novel imaging method for local IMD analysis in superconducting resonators, highlighting differences in physical mechanisms between IMD orders.

Findings

Second and third order IMD have different spatial distributions.

Second order IMD is more sensitive to magnetic fluxons.

Technique enables detailed investigation of IMD mechanisms.

Abstract

Using a near-field microwave technique, two-dimensional images have been made of the second and third order intermodulation distortion (IMD) of Tl2Ba2CaCu2O8 and YBa2Cu3O7 thin film microwave resonators. It was found that second and third order IMD do not have identical spatial distributions, which indicates that physical mechanisms play different roles in their generation. This technique enables the investigation of the roles of these mechanisms. As an illustration, the sensitivity to magnetic fluxons of the two orders is described, with second order being more sensitive to fluxon density.