Spatial correlation of linear and nonlinear electron transport in superconducting microwave resonator: laser scanning microscopy analysis

TL;DR

This study uses laser scanning microscopy to spatially analyze linear and nonlinear microwave properties in a superconducting resonator, revealing resistive sources of nonlinearity and the influence of structural features.

Contribution

It provides detailed spatial correlation analysis of linear and nonlinear microwave responses in a superconducting resonator using LSM, highlighting resistive origins of nonlinearity.

Findings

Resistive regions are the main source of microwave nonlinearity.

Twin-domain structure influences the nonlinear response.

Edge peaks in RF current correlate with nonlinear behavior.

Abstract

Spatially-resolved techniques of laser scanning microscopy (LSM) have been used to image simultaneously the spatial variations of (i) rf current flow, J$_RF$(x,y), of (ii) areas of resistive dissipation and (iii) the sources of microwave nonlinearity (NL) in an operating superconducting resonator. The RF power dependent spatial evolution of these linear and NL microwave properties in the meander strip YBCO/LAO superconducting resonator have been LSM probed at different temperatures below Tc. The influence of both topologies of the twin-domain YBCO structure and of J$_RF$(x,y) peaks at the edges of superconducting strip line on its NL properties was analyzed in detail with a micron-scale spatial resolution. Result shows the resistive origin of the dominant sources of microwave NLs