Spatially resolved critical current limitations in YBa2Cu3O7 multilayer structures

Current flow in YBa2Cu3O7/PrBa2Cu3O7 multilayer structures has been studied using low temperature, scanning electron microscope, beam-induced voltage contrast. Specialized data acquisition has been used to limit thermalization effects and improve resolution. For both via hole contacts and crossovers, the lowest critical current densities were found at steps where the superconductor tracks climb up or down over patterned edges of the insulator.