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

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