Elastic scattering and the current‐voltage characteristics of superconducting Nb‐InAs‐Nb junctions

Superconducting niobium contacts are attached to a 0.8-mum-long epitaxially grown InAs channel sandwiched between insulating InGaAs layers. The current-voltage characteristics show nonlinearities at submultiples of the superconducting energy gap indicative of multiple-Andreev reflections. We demonstrate that an increase in the elastic scattering rate in the InAs channel, caused by Ar-ion etching, diminishes the order of Andreev reflections and explains the overall shape of the current-voltage characteristics